Archive-name: comp-speech-faq/part3
Last-modified: 1995/01/19

              COMP.SPEECH FAQ POSTING - PART 3/3

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FAQ SECTION 5 - Speech Synthesis

   Speech synthesis is the task of transforming written input to spoken
   output. The input can either be provided in a graphemic/orthographic
   or a phonemic script, depending on its source.
   There are several algorithms. The choice depends on the task they're
   used for. The easiest way is to just record the voice of a person
   speaking the desired phrases. This is useful if only a restricted
   volume of phrases and sentences is used, e.g. messages in a train
   station, or schedule information via phone. The quality depends on the
   way recording is done.
   More sophisticated but worse in quality are algorithms which split the
   speech into smaller pieces. The smaller those units are, the less are
   they in number, but the quality also decreases. An often used unit is
   the phoneme, the smallest linguistic unit. Depending on the language
   used there are about 35-50 phonemes in western European languages,
   i.e. there are 35-50 single recordings. The problem is combining them
   as fluent speech requires fluent transitions between the elements. The
   intellegibility is therefore lower, but the memory required is small.
   A solution to this dilemma is using diphones. Instead of splitting at
   the transitions, the cut is done at the center of the phonemes,
   leaving the transitions themselves intact. This gives about 400
   elements (20*20) and the quality increases.
   The longer the units become, the more elements are there, but the
   quality increases along with the memory required. Other units which
   are widely used are half-syllables, syllables, words, or combinations
   of them, e.g. word stems and inflectional endings.
   The following are good introductory books/articles.
     * Douglas O'Shaughnessy -- Speech Communication: Human and Machine
       Addison Wesley series in Electrical Engineering: Digital Signal
       Processing, 1987.
     * D. H. Klatt, "Review of Text-To-Speech Conversion for English",
       Jnl. of the Acoustic Society of America (JASA), v82, Sept. 1987,
       pp 737-793.
     * "Talking Machines, Theories, Models and Designs" Eds, G. Bailly &
       C. Benoit (Elsevier: North Holland)
     * I. H. Witten. Principles of Computer Speech. (London: Academic
       Press, Inc., 1982).
     * John Allen, Sharon Hunnicut and Dennis H. Klatt, "From Text to
       Speech: The MITalk System", Cambridge University Press, 1987.
   Please email any updates, corrections or additions to the following
   list. The range of commercially available synthesis software is
   growing rapidly so any help in keeping up to date will be appreciated.
    Orator Text-to-Speech Synthesizer
     * Platform: SUN SPARC, Decstation 5000. Written in C, and
       therefore portable to other UNIX platforms. Some successful ports:
       HP, RS-6000, PC-Unix [Linux].
     * Description: Sophisticated speech synthesis package. Has text
       preprocessing (for abbreviations, numbers), acronym rules, and
       human-like spelling routines. Natural-sounding synthesis based on
       demisyllable concatenation.
       Has high accuracy for pronunciation of names of people, places and
       businesses in America; good accuracy for English text; rules for
       stress and intonation marking; various methods of user control and
       customization at most stages of processing.
       A new version of the ORATOR system is under development. Both
       ORATOR and this new "ORATOR II" system are capable of very good
       general text synthesis. The ORATOR II system has a more
       natural-sounding voice.
     * Hardware: Runs on common SPARC or Decstation workstations, using
       their internal audio output capability. Recommend at least 16M of
     * Availability and Pricing: Contact Bellcore's Licensing Office
       (1-800-527-1080) or email Anthony Lindsey
    Text to phoneme program (1)
     * Platform: unknown
     * Description: Text to phoneme program. Based on Naval Research
       Lab's set of text to phoneme rules.
     * Availability: by anonymous ftp
    Text to phoneme program (2)
     * Platform: unknown
     * Description: Text to phoneme program.
     * Availability: by anonymous ftp
    Text to phoneme program (3)
     * Description: A public domain version of the same Naval Research
       Lab text to phoneme rules.
     * Availability: By anonymous ftp
    Text to speech program
     * Description: A implementation of the Klatt phoneme to waveform
       speech synthesiser.
     * Availability: By anonymous ftp
    "Speak" - a Text to Speech Program
     * Platform: Sun SPARC
     * Description: Text to speech program based on concatenation of
       pre-recorded speech segments. A function library can be used to
       integrate speech output into other code.
     * Hardware: SPARC audio I/O
     * Availability: by anonymous ftp
    TheBigMouth - a Text to Speech Program
     * Platform: NeXT
     * Description: Text to speech program based on concatenation of
       pre-recorded speech segments. NeXT equivalent of "Speak" for Suns.
     * Availability: try NeXT archive sites such as
    TextToSpeech Kit
     * Platform: NeXT Computers
     * Description: The TextToSpeech Kit does unrestricted conversion
       of English text to synthesized speech in real-time. The user has
       control over speaking rate, median pitch, stereo balance, volume,
       and intonation type. Text of any length can be spoken, and
       messages can be queued up, from multiple applications if desired.
       Real-time controls such as pause, continue, and erase are
       included. Pronunciations are derived primarily by dictionary
       look-up. The Main Dictionary has nearly 100,000 hand-edited
       pronunciations which can be supplemented or overridden with the
       User and Application dictionaries. A number parser handles numbers
       in any form. A letter-to-sound knowledge base provides
       pronunciations for words not in the Main or customized
       dictionaries. Dictionary search order is under user control.
       Special modes of text input are available for spelling and
       emphasis of words or phrases. The actual conversion of text to
       speech is done by the TextToSpeech Server. The Server runs as an
       independent task in the background, and can handle up to 50 client
     * Misc: The TextToSpeech Kit comes in two packages: the Developer
       Kit and the User Kit. The Developer Kit enables developers to
       build and test applications which incorporate text-to-speech. It
       includes the TextToSpeech Server, the TextToSpeech Object, the
       pronunciation editor PrEditor, several example applications,
       phonetic fonts, example source code, and developer documentation.
       The User Kit provides support for applications which incorporate
       text-to-speech. It is a subset of the Developer Kit.
     * Hardware: Uses standard NeXT Computer hardware.
     * Cost:
          + TextToSpeech User Kit: $175 CDN ($145 US)
          + TextToSpeech Developer Kit: $350 CDN ($290 US)
          + Upgrade from User to Developer Kit: $175 CDN ($145 US)
     * Availability: Trillium Sound Research
    1500, 112 - 4th Ave. S.W., Calgary, Alberta, Canada, T2P 0H3
    Tel: (403) 284-9278 Fax: (403) 282-6778
    Order Desk: 1-800-L-ORATOR (US and Canada only)
    SGI Developers Toolbox Synthesiser
     * Platform: SGI
     * Description: The SGI Developer Toolbox 4.0 CDROM contains a
       basic public domain text-to-speech program in the publics/speak
       directory. The directory includes man pages and source.
     * Availability: on the SGI Developer Toolbox 4.0 CDROM
     * Platform: Various (including Solaris2.3, SunOS4.1.3, HPUX, SGI
       Irix4.x, Linux)
     * Description:Public domain text-to-speech systm assembled from a
       variety of sources. It supports CMU and "beep" format dictionaries
       and now utilises stress marks in the dictionary in synthesising
     * Price: Free
     * Availability: by anonymous ftp from
    SENSYN speech synthesizer
     * Platform: PC, Mac, Sun, and NeXt
     * Rough Cost: $300
     * Description: This formant synthesizer produces speech waveform
       files based on the (Klatt) KLSYN88 synthesizer. It is intended for
       laboratory and research use. Note that this is NOT a
       text-to-speech synthesizer, but creates speech sounds based upon a
       large number of input variables (formant frequencies, bandwidths,
       glottal pulse characteristics, etc.) and would be used as part of
       a TTS system. Includes full source code.
     * Availability: Sensimetrics Corporation
    64 Sidney Street, Cambridge MA 02139.
    Fax: (617) 225-0470; Tel: (617) 225-2442.
     * Platform: PC?
     * Availability: By anonymous ftp as a self extracting DOS archive.
     * Requirements: May require special TI product(s), but all source
       is there.
    CSRE: Canadian Speech Research Environment
     * Platform: PC
     * Cost: Distributed on a cost recovery basis.
     * Description: CSRE is a software system which includes in
       addition to the Klatt speech synthesizer, SPEECH ANALYSIS and
       EXPERIMENT CONTROL SYSTEM. A paper about the whole package can be
       found in:
          + Jamieson D.G. et al, "CSRE: A Speech Research Environment",
            Proc. of the Second Intl. Conf. on Spoken Language
            Processing, Edmonton: University of Alberta, pp. 1127-1130.
     * Hardware: Can use a range of data aqcuisition/DSP hardware.
     * Availability: For more information contact
    Krystyna Marciniak
    Tel (519) 661-3901 Fax (519) 661-3805.
   For technical information email
     * Note: A more detailed description is given in Section 1.9 on
       speech environments.
    Eloquence (currently an alpha release)
     * Platform: Windows and Solaris
     * Description: Software based text-to-speech package. Generates
       waveforms completely algorithmically instead of by concatenating
       waveforms, for maximum flexibility and naturalism. For instance,
       when the user requests a deeper voice, the software simulates a
       larger vocal tract, instead of simply pitch-shifting samples.
       Uses high-level linguistic parsing, which obviates the need for a
       huge dictionary. Handles numbers, acronyms, currency, etc.
       Includes a set of annotation symbols, for placing stress on
       particular words, expressing excitement/boredom, etc. Also allows
       phonetic input. The final version, including support for Windows
       DDE and OLE and UNIX Sockets, will be released by the end of 1994.
       Produces male and female voices for General American English.
       Dialects under development include Alabama, Brooklyn, and Boston.
     * Price: $5000 (unconfirmed)
     * Availability:
    Eloquent Technology, Inc.
    2389 North Triphammer Road
    Ithaca, NY 14850
    Ph: (607) 607-266-7025 Fax: (607) 607-266-7030
     * Platform: UNIX and PC
     * Cost: 100 pounds sterling (from academic institutions and
     * Description: A C version of the JSRU system, Version 2.3 is
       available. It's written in Turbo C but runs on most Unix systems
       with very little modification. A Form of Agreement must be signed
       to say that the software is required for research and development
     * Contact: Dr. E.Lewis
    Klatt-style synthesiser
     * Platform: Unix
     * Cost: Free
     * Description: Software posted to comp.speech in late 1992.
     * Availability: By anonymous ftp from the comp.speech archives
     * Description: Speech synthesis hardware and software. Detailed
       information on DECtalk and other DEC products is available on a
       World-Wide Web site.
   For specific information on DECtalk, check out this www url:
    Speech Manager and PlainTalk
     * Platform: Macintosh
     * Cost: Free
     * Description: Apple's new text-to-speech system extension(s) that
       enable applications (listed below) to perform text-to-speech
       conversion. The Speech Manager runs on most Macs, but PlainTalk
       (and the high quality voices) requires a 68020 Mac or better.
     * Availability: By anonymous ftp from:
   There are 3 files in this directory:
        6273632 Aug 14 22:51 macintalk-pro.hqx
                PlainTalk Text-To-Speech 1.0 speech synthesizer extension
                (includes Female Voice, Compressed); TTS Female Voice;
                TTS Male Voice; and TTS Male Voice, Compressed. Requires
                68020 or better!
        370108 Aug 13 04:30 speech-manager-docs.hqx
                Apple DocViewer format (Inside Macintosh style, no
                installation instructions - just drag everything onto
                your closed System Folder).
        262569 Aug 7 07:01 speech-manager.hqx
                Speech Manager 1.1.1 (includes Marvin's voice) and
                MacInTalk Voices 1.1.1 (9 more voices). Runs most Macs.
    Various Mac Speech Output Applications
     * Platform: Macintosh
     * Cost: Free (except for At Ease)
     * Description: Some of the Speech Manager aware text-to-speech
       (TTS) applications, etc. are listed below (there are more on the
       Apple Developer CD-ROMs).
Application, etc.  Source            Comments
_________________ ________  _________________________________________________
AddressSpeech     info-mac  4D talking address book (from Speech Pack 2.0)
At Ease 2.0    MacWarehouse Friendly desktop that speaks file names
At Ease 2.0 WG MacWarehouse Friendly desktop that speaks file names
Eliza 3.1            AOL    Talking Eliza (Rogerian psych therapist)
FB speech      Inside Basic Mag, volume 3, no. 6. FutureBasic demo
FB Speech demo Inside Basic Mag, volume 3, no. 7. FutureBasic demo
Fortune 1.1       info-mac  Like a talking UNIX fortune command - slick
Homer 0.92d9  GUI IRC client, assign nicks voices - slick
MacMessage 1.0  FirstClassBBS  Share talking messages/customizable startup
Say               info-mac  MPW Tool which converts standard input to speech
ScriptTools 1.2   info-mac  Write AppleScript scripts to say text messages
Siege Watch 1.01f info-mac  Wryly political speaking clock
SoToSpeak1.0.0b10 info-mac  Two voice conversation (also see Fortune's About)
Speak It!         info-mac  Type in a message and have it spoken
Speaker 1.11      info-mac  Simple text file editor, speaks on CR, macros
Speecher 1.2.1    info-mac  Customizable word pronunciation/substitution
SpeechManagerdemo info-mac  Command line interface, C source, aka -explorer
Speech Pack 2.0   info-mac  4th Dimension external, add speech to database
SpeechUnitEx      info-mac  Pascal source code for speech in Lab 7
speek-02b         info-mac  Speech XCMD for HyperCard
TalkingClockPro2.0info-mac  AppleScriptable talking clock extension (2.0b0)
TeachText 7.2      AV Mac   Apple's talking TeachText (simple editor w/QT)
Tex-Edit 1.9         AOL    Talking word processor, McSink like, modeming
VoiceDemo 1.0.1   info-mac  Bare bones phrase talker
Welcome!v1.3.1    info-mac  A talking Welcome to Macintosh startup
?                     ?     Talking Plug-In-Module for MS Word 5,
                               experimental, unsupported, buggy, beware!
Speech Rhythms       AOL    A cool text file for one of the above apps
     * Sources:
          + AOL = America Online
          + info-mac = {ftp, ftp
  , et al.}
          + MacWarehouse = (800) 255-6227
     * Misc: Apple's work in spoken language technologies and systems
       is described in:
          + Lee, Kai-Fu. "The Conversational Computer: An Apple
            Perspective." (Keynote Speech) In Proc. Eurospeech in Berlin,
            September, 1993.
     * Platform: Macintosh
     * Cost: Free
     * Description: Formant based speech synthesis. There is also a
       program called "tex-edit" which apparently can pronounce English
       sentences reasonably using Macintalk.
     * Note: MacinTalk doesn't run reliably on Macintosh's with new
       sound hardware under the lastest OS (System 7.1 w/HUD 2.0). More
       recent software is listed above.
     * Availability: By anonymous ftp from many archive sites (have a
       look on archie if you can). tex-edit is on many of the same sites.
    Monologue by Creative Labs
     * Platform: PC Windows plus SoundBlaster 16
     * Cost: $99.00 or free with some MultiMedia packages
     * Description: Phoneme based speech synthesis software which
       provides output on Sound Blaster compatible audio cards. It
       includes a dictionary of words that are "exceptions" together with
       a a dictionary manager for modifying those words. It can be used
       as a stand alone program with Windows' Clipboard or as a DDE
       server dynamically linked (DLL) to a program you write.
     * Cost: $99.00 or free with some MultiMedia packages
     * Contact:
    Creative Labs Inc.
    1901 McCarthy Boul, Milpitas, CA 95035, USA
    Tel: 408-428-6622 Fax: 408-428-6633 BBS: 408-428-6660
    OR Creative Technology Ltd.
    67 Ayer Rajah Crescent #03-18, Singapore 0513
    Tel: 65-870-0433 Fax: 65-773-0353 BBS: 65-776-2423
    Lernout & Hauspie Text-To-Speech SDK
     * Platform: IBM-Compatible
     * Description: The L&H; Text-to-Speech software developers kit is
       able to integrate text-to-speech technology with your own or
       existing PC applications under Microsoft Windows 3.1. This
       software will allow conversion of written text into clear human
       sounding synthetic speech.
     * Requirements: IBM-compatible PC 386 DX(33Mhz) or higher, 8Mb
       RAM, MS DOS 5.0(or higher), MS Windows 3.1 (or higher), Compiler
       and linker: Microsoft(R) Visual C++ or Borland C++, Windows(TM)
       3.1 compatible sound card, preferably 16 bit e.g. Soundblaster,
       Windows Sounds System, Pro Audio Spectrum
     * Price: Unconfirmed $1,999 per copy, and $499 per each additional
       language (American English, French, German, or Spanish).
     * Contact: USA (617) 932-4118
     * Platform: PC
     * Description: Shareware package is a speech 'screen reader' which
       is used by many blind users.
     * Availability: By anonymous ftp
   Get the files and
    Narrator - narrator.device
     * Platform: Amiga
     * Description: Formant based speech synthesis. Includes a
       Engish-to-phoneme translation library, and a SPEAK: pseudo-device
       for speech output.
     * Hardware: Standard Amiga hardware
     * Availability: Part of AmigaOS
    Infovox Product Range
     * Description: Multilingual Text-to-speech systems, languages
       available: American English, British English, German, French,
       Spanish, Italian, Swedish, Norwegian, Icelandic, Danish and
     * Product name: INFOVOX 500, PC BOARD
          + Product description: Half length expansion board for IBM PC,
            XT, AT, PS/2 model 30 or compatible personal computers. The
            board can also be connected via the serial port. Language and
            control program for downloading into RAM or mounted on
          + Platform: for IBM PC, XT, AT, PS/2 model 30 or compatible
     * Product name: INFOVOX 600, OEM BOARD
          + Product description: OEM board built with CMOS IC's. Language
            and control program are stored in on-board fixed memory.
          + Platform: any, Interface: 9-pole D-SUB (RS 232-C) 300-9600
     * Product name: INFOVOX 700, DESKTOP UNIT
          + Product description: Desktop unit with built in Infovox 600
            to be connected to any computer or terminal via an RS 232-C
            serial interface. Built in loudspeaker and rechargable
            battery for 4 hours use, and control knobs for continuous
            control of speech volume and speed.
          + Platform: any
     * Product name: INFOVOX 650, OEM BOARD
          + Product description: OEM-board built with CMOS IC's. Language
            and control program are stored in on-board memory.
          + Platform:any, Interface: 9 pole D-SUB (RS 232-C) 300-9600
     * Product name: INFOVOX 750, DESKTOP UNIT
          + Product description: Desktop unit with built in Infovox 650
            to be connected to any computer or terminal via an RS 232-C
            serial interface. Built in loudspeaker and rechargable
            battery for 5 hours use, and a control knob for continuous
            control of speech volume.
          + Platform: any
     * Misc: Infovox multi-lingual Text-to-Speech Technologies can
       interface with Apple's PlainTalk System. It enables Apple Third
       party developers to write application software with synthetic
       speech output using their usual Apple Plain Talk Text-to-Speech
       interface. Software already written for the English speaking
       market using Apple Plain Talk can be now distributed worldwide,
       provided message strings are translated.
     * Contact:
    Telia Promotor Infovox AB
    TTS Sales Division
    P.O. Box 2069
    S-171 02 Solna, Sweden
    Ph: +46 8 764 35 00 Fax: +46 8 735 78 76
     * The following is a list of speech related software available from
       SIMTEL-20 and its mirror sites for PCs.
     * The SIMTEL internet address is WSMR-SIMTEL20.Army.Mil
       [] Try looking at your nearest archive site first.
       [Note: problems have been reported in accessing this site - does
       anyone know a new address?]
Directory PD1: MSDOS.VOICE
 Filename   Type Length   Date   Description
 AUTOTALK.ARC  B   23618  881216  Digitized speech for the PC
 CVOICE.ARC    B   21335  891113  Tells time via voice response on PC
 HEARTYPE.ARC  B   10112  880422  Hear what you are typing, crude voice synth.
 HELPME2.ARC   B    8031  871130  Voice cries out 'Help Me!' from PC speaker
 SAY.ARC       B   20224  860330  Computer Speech - using phonemes
 SPEECH98.ZIP  B   41003  910628  Build speech (voice) on PC using 98 phonemes
 TALK.ARC      B    8576  861109  BASIC program to demo talking on a PC speaker
 TRAN.ARC      B   39766  890715  Repeats typed text in digital voice
 VDIGIT.ZIP    B  196284  901223  Toolkit: Add digitized voice to your programs
 VGREET.ARC    B   45281  900117  Voice says good morning/afternoon/evening



FAQ SECTION 6 - Speech Recognition

   Automatic speech recognition is the process by which a computer maps
   an acoustic speech signal to text.
   Automatic speech understanding is the process by which a computer maps
   an acoustic speech signal to some form of abstract meaning of the
   Doug Danforth provides a detailed account in article 253 in the
   comp.speech archives. A summary is provided below. It is also
   available by anonymous ftp
    Here is a simple recognizer that should give you 85%+ recognition
   accuracy. The accuracy is a function of the words you have in your
   vocabulary. Long distinct words are easy. Short similar words are
   hard. You can get 98+% on the digits with this recognizer.
     * Find the begining and end of the utterance.
     * Filter the raw signal into frequency bands.
     * Cut the utterance into a fixed number of segments.
     * Average data for each band in each segment.
     * Store this pattern with its name.
     * Collect training set of about 3 repetitions of each pattern
     * Recognize unknown by comparing its pattern against all patterns in
       the training set and returning the name of the pattern closest to
       the unknown.
   Many variations upon the theme can be made to improve the performance.
   Try different filtering of the raw signal and different processing
   Q6.7 contains information on public domain speech recognition
   software: Lotec and Myers' Hidden Markov Model software.
   A speaker dependent system is developed to operate for a single
   speaker. These systems are usually easier to develop, cheaper to buy
   and more accurate, but not as flexible as speaker adaptive or speaker
   independent systems.
   A speaker independent system is developed to operate for any speaker
   of a particular type (e.g. American English). These systems are the
   most difficult to develop, most expensive and accuracy is lower than
   speaker independent systems. However, they are more flexible.
   A speaker adaptive system is developed to adapt its operation to the
   characteristics of new speakers. It's difficulty lies somewhere
   between speaker independent and speaker dependent systems.
   The size of vocabulary of a speech recognition system affects the
   complexity, processing requirements and the accuracy of the system.
   Some applications only require a few words (e.g. numbers only), others
   require very large dictionaries (e.g. dictation machines). There are
   no established definitions, however, try
     * small vocabulary - tens of words
     * medium vocabulary - hundreds of words
     * large vocabulary - thousands of words
     * very-large vocabulary - tens of thousands of words.
   An isolated-word system operates on single words at a time - requiring
   a pause between saying each word. This is the simplest form of
   recognition to perform because the end points are easier to find and
   the pronunciation of a word tends not affect others. Thus, because the
   occurrences of words are more consistent they are easier to recognise.
   A continuous speech system operates on speech in which words are
   connected together, i.e. not separated by pauses. Continuous speech is
   more difficult to handle because of a variety of effects. First, it is
   difficult to find the start and end points of words. Another problem
   is "coarticulation". The production of each phoneme is affected by the
   production of surrounding phonemes, and similarly the the start and
   end of words are affected by the preceding and following words. The
   recognition of continuous speech is also affected by the rate of
   speech (fast speech tends to be harder).
   A wide variety of techniques are used to perform speech recognition.
   There are many types of speech recognition. There are many levels of
   speech recognition / analysis / understanding.
   Typically speech recognition starts with the digital sampling of
   speech. The next stage is acoustic signal processing. Most techniques
   include spectral analysis; e.g. LPC analysis, MFCC, cochlea modelling
   and many, many more.
   The next stage is recognition of phonemes, groups of phonemes and
   words. This stage can be achieved by many processes such as DTW
   (Dynamic Time Warping), HMM (hidden Markov modelling), NNs (Neural
   Networks), expert systems and combinations of techniques. HMM-based
   systems are currently the most commonly used and most successful
   Most systems utilise some knowledge of the language to aid the
   recognition process.
   Some systems try to "understand" speech. That is, they try to convert
   the words into a representation of what the speaker intended to mean
   or achieve by what they said.
   Some reviews of speech recognition for personal computers:
     * "Seybold Report on Desktop Publishing" published a nine-page,
       head-to-head comparison of Dragon's DOS software with IBM's OS/2
       software. March 7, 1994; Volume 8, Number 7; Pages 3-11;
       ISSN:0889-9762; Seybold Publications, P.O. Box 644, Media, PA
       19063 USA, phone (610) 565-2480.
     * McGraw-Hill Inc.'s "BYTE, the Magazine of Technology Integration,"
       published a two-page review of IBM's Personal Dictation System
       software. May 1994; Volume ?, Number ?; Pages 145-146;
       ISSN:0360-5280; Editorial, Executive, and Circulation address: One
       Phoenix Mill Lane, Peterborough, NH 03458 USA, phone ?
   Some general introduction books on speech recognition technology:
     * Fundamentals of Speech Recognition; Lawrence Rabiner & Biing-Hwang
       Juang Englewood Cliffs NJ: PTR Prentice Hall (Signal Processing
       Series), c1993 ISBN 0-13-015157-2
     * Speech recognition by machine; W.A. Ainsworth London: Peregrinus
       for the Institution of Electrical Engineers, c1988
     * Speech synthesis and recognition; J.N. Holmes Wokingham: Van
       Nostrand Reinhold, c1988
     * Douglas O'Shaughnessy -- Speech Communication: Human and Machine
       Addison Wesley series in Electrical Engineering: Digital Signal
       Processing, 1987.
     * Electronic speech recognition: techniques, technology and
       applications edited by Geoff Bristow, London: Collins, 1986
     * Readings in Speech Recognition; edited by Alex Waibel & Kai-Fu
       Lee. San Mateo: Morgan Kaufmann, c1990
   More specific books/articles:
     * Hidden Markov models for speech recognition; X.D. Huang, Y. Ariki,
       M.A. Jack. Edinburgh: Edinburgh University Press, c1990
     * Automatic speech recognition: the development of the SPHINX
       system; by Kai-Fu Lee; Boston; London: Kluwer Academic, c1989
     * Prosody and speech recognition; Alex Waibel (Pitman: London)
       (Morgan Kaufmann: San Mateo, Calif) 1988
     * S. E. Levinson, L. R. Rabiner and M. M. Sondhi, "An Introduction
       to the Application of the Theory of Probabilistic Functions of a
       Markov Process to Automatic Speech Recognition" in Bell Syst.
       Tech. Jnl. v62(4), pp1035--1074, April 1983
     * R. P. Lippmann, "Review of Neural Networks for Speech
       Recognition", in Neural Computation, v1(1), pp 1-38, 1989.
   The following packages are presented in no particular order.
    HM2007 - Speech Recognition Chip
     * Description: HM2007 is a 48-pin single chip CMOS voice
       recognition LSI circuit with on-chip analog front end, voice
       analysis, recognition process and system control functions. A 40
       word isolated-word voice recognition system can be composed of an
       external microphone, keyboard, SRAM and a few other components.
       When combined with a microprocessor, an intelligent recognition
       system can be built. A demo board for this chip is being
       distributed by The Summa Group.
     * Cost: Approx US$30 for the HM2007 and US$100 for the demo board.
     * Warning: Several people have reported problems in obtaining
       small numbers of this chip (say less than 10). It appears that the
       distributors (include the one listed below) are only interested in
       large volumes. If you know of a good source please send it in for
       inclusion in the FAQ.
     * Contact: 
    The Summa Group Limited
    One California Street, Suite #1940,
    San Francisco, CA 94111
    Ph: (415) 288-0390
    Voice Blaster Ver. 4.0
     * Platform: IBM AT or higher, DOS or Wndows 3.1
     * Description: Uses a Sound Blaster or compatible board. Contains
       a microphone headset and a connector for LPT1:. A printer can
       still be used on LPT1:. Will recognize 1024 words that are trained
       by the operator. Each word activates a macro that can enter an
       ascii word on the screen or into a word processor or invoke a
       batch file. An optional footswitch may be installed. Software to
       run under DOS or Windows 3.1 is included.
     * Cost: Around $150 Canadian.
     * Contact: 
    COVOX Inc.
    675 Conger Street
    Eugene, Oregon, 97402, USA
    Ph: (503) 342-1271 Fax: (503) 342-1283
    BBS: (503) 342-4135
     * Platform: MS-DOS, SCO UNIX
     * Description: Isolated word and continuous speech modes, speaker
       dependant and (limited) speaker independent. Vocab size is 255
       words or up to a fixed memory limit - but it is possible to
       dynamically load different words for effectively unlimited number
       of words.
     * Rough Cost: Approx US $1,000-$1,500
     * Requirements: Cost includes one Votan Voice Recognition ISA-bus
       board for 386/486-based machines. A software development system is
       also available for DOS and Unix.
     * Misc: Up to 8 Votan boards may co-exist for 8 simultaneous voice
       users. A telephone interface is also available. There is also a
       4GL and a software development system. Apparently there is more
       than one version - more info required.
     * Contact: 800-877-4756, 510-426-5600
    Entropic's HTK (HMM Toolkit)
     * Platform: Range of Unix platforms.
     * Description: HTK is a software toolkit for building continuous
       density HMM based speech recognisers. It consists of a number of
       library modules and a number of tools. Functions include speech
       analysis, training tools, recognition tools, results analysis, and
       an interactive tool for speech labelling. Many standard forms of
       continuous density HMM are possible. Can perform isolated word or
       connected word speech recognition. It van model whole words, sub-
       word units. Can perform speaker verification and other pattern
       recognition work using HMMs. HTK is now integerated with the
       ESPS/Waves speech research environment which is described in
       Section 1.8.
     * Misc: The availability of HTK changed in early 1993 when
       Entropic obtained exclusive marketing rights to HTK from the
       developers at Cambridge.
     * Cost: On request.
     * Contact: 
    Entropic Research Laboratory,
    600 Pennsylvania Ave, S.E. Suite 202,
    Washington, D.C. 20003, USA
    Phone: (202) 547-1420.
    email -
    DragonDictate version 3.0
     * Platform: PC
     * Description: Speaker-adaptive recognition system for discrete
       speech. Provides 110,000 word dictionary and also allows user to
       add words. Active vocabulary of 5,000, 30,000, or 60,000 words.
       Allows dictation into almost all DOS applications (word
       processors, spreadsheets, etc.) and hands-free operation of the
     * Cost:Prices including audio board and high-quality headset
          + US$695 (5,000 word Starter Edition)
          + US$995 (30,000 word Classic Edition)
          + US$1,995 (60,000 word Power Edition)
     * Requirements: Minimum of 33 Mhz 486 with 8-16M memory and at
       least 29M disk space (depending on product), one 8-bit slot, DOS
       5.0 and up (also runs in a DOS box under Windows or OS/2).
     * Contact: 
    Dragon Systems, Inc.
    320 Nevada Street
    Newton, MA 02160, USA
    Tel: 1-617-965-5200, Fax: 1-617-527-0372
    DragonDictate for Windows
     * Platform: PC
     * Description: Speech-to-text dictation system. Discrete speech;
       speaker- adaptive. Also provides command/control and mouse
       movement for hands-free operation of Windows. Comes with a 120,000
       word pronunciation dictionary; users can also add their own words
       or phrases. Dictate directly into any application.
     * Rough Cost:Prices including software, documentation and
          + DragonDictate Starter Edition (5,000 words active) -- $395
          + DragonDictate Classic Edition (30,000 words active) -- $695
          + DragonDictate Power Edition (60,000 words active) -- $1,695
     * Requirements: 486/33, 7-10 MB dedicated RAM (depending on
       edition), Windows 3.1 or later. Supported sound boards: Media
       Vision Pro Audio Studio 16, Creative Labs Sound Blaster 16,
       Microsoft Windows Sound System, IBM Audio Capture/Playback
     * Contact:
    Dragon Systems, Inc.
    320 Nevada Street
    Newton, MA 02160, USA
    Phone: (617)965-5200 Fax: (617)527-0372
     * Platform: PC
     * Description: Programmer's toolkit for developing speech-aware
       DOS or Windows applications. Recognizes continuously spoken digits
       and discretely spoken words or phrases. Up to 1,000 words can be
       active at one time. Use words from 110,000 word dictionary
       (included) and/or develop your own word models.
     * Cost: 
          + US$1,995 (developer's kit)
          + US$595 (end-user system)
     * Requirements: Minimum of 20 Mhz 386 (larger vocabulary requires
       faster processor) with at least 5M memory and at least 19M disk
       space (depending on vocabulary size), DOS 5.0 and up, Windows 3.1
       and up, Borland C or C++ or Microsoft C or C++. Also requires IBM
       M-ACPA card available from IBM or Dragon Systems ($325).
     * Contact: 
    Dragon Systems, Inc.
    320 Nevada Street,
    Newton, MA 02160, USA
    Tel: 1-617-965-5200, Fax: 1-617-527-0372
    IBM VoiceType Dictation
    OR: Osborne Personal Dictation System (in Australia)
     * Platform: Intel I486 & IBM OS/2
     * Description: Independent Speaker, discrete speech dictation with
       navigation. Navigation does not require setup, most applications
       are automatically speech enabled by dynamic control analysis.
       Dictation averages 70WPM with 95% accuracy and uses statistical
       trigram modelling. The base system is 22K words, other
       vocabularies available for specific industries.
     * Requirements: 486SX or above, 16MB Ram, 30MB File space,
       Dictation Adapter
     * Cost: Software $495 (includes mic) / Hardware $495
     * Misc 1: A Windows version is now available.
     * Misc 2: Based on IBM Tangora Technology
     * Availability: US English. Other languages (UK, FR, GR, IT, and
       ES) available 3Q94.
     * Contact: US Contact 1-800-TALK-2-ME or 1-914-766-9252.
    VoiceServer for Windows
     * Platform: PC
     * Description: Speaker dependent, each with an independent
       directory. Isolated word. Upto 1000 words/user, 300 words/window.
       1 word occupies 2Kb on hard disk. Can be used to control Windows
       applications by issuing voice commands instead of menu selection.
     * Rough Cost: 292 Pounds(UK)
     * Requirements: None
     * Misc: Price includes a half-sized AT voice card (including a
       DSP), software, documentation & a microphone (attachable to
       keyboard or speaker). A light-weight high-spec headset is an
       optional extra.
     * Contact: 
    Mark Redwood
    Applied Voice Technologies
    26 Danbury Street, Islington,
    London, UK, N1 8JU
    Ph: + 44 71 454 1224 : Fax: + 44 71 454 1225
    IN3 Voice Command for Windows
     * Platform: PC with Windows 3.1
     * Description: IN3 is now available for MS-Windows. Users can call
       applications to the foreground with voice commands. Once the
       application is called, the user may enter commands and data with
       voice commands. Voice macros can reduce the strain of repetitive
       stress injuries (RSI) such as Carpel Tunnel Syndrome (CTS) by
       replacing heavy repetitive keyboard hammering with simple voice
       operations. Voice macros take complex operations and reduce them
       to simple verbal commands. Voice input can provide new facilities
       for tasks which could not easily have been otherwise performed
       without the multiple axis of input. IN3 is hardware-independent,
       users with any Windows-compatible audio add speech recognition to
       the desktop. IN3 works with either 8 bit or 16 bit Windows audio
       boards. IN3 is based on continuous word-spotting technology. A
       developer API is also available for creating voice-enabled
     * Price: $179 U.S.
     * Requirements: PC with 80386 processor or better, Microsoft
       Windows 3.1, and Windows compatible audio system with microphone.
     * Misc: Fully functional demos are available on Compuserve in
       various Multimedia and CAD forums. Demos are also available from
       "America on Line", the archive sites, and
       various BBS systems. It is also available by anonymous ftp
   An equivilant Sun product is described below.
     * Contact: 
    Brantley Kelly
    Email: CIS: 75120,431
    FAX: 1-404-925-7924 Phone: 1-404-925-7950
    Command Corp. Inc, 3675 Crestwood Parkway, Duluth GA 30136, USA
    IN3 Voice Command
     * Platform: Sun SPARCstation
     * Description: IN3 provides a secure, robust, word spotting,
       continuous speech recognition facility for the Sun OS or Solaris
       operating systems. The recognition system is a secure operating
       system facility capable of working with various interfaces,
       microphones, and devices. The operating system interface works
       with native UNIX outside of X Windows as well as provides enhanced
       X Windows facilities including named window support. The user
       interface provides a means to quickly create commands on the fly
       for replacing long strings and complex operations with voice
       macros. [Voice macros can reduce the strain of repetitive stress
       injuries (RSI) such as Carpel Tunnel Syndrome (CTS) by replacing
       heavy repetitive keyboard hammering with simple voice operations.
       ] The IN3 user interface works with generic X servers and window
       managers. A developer API is also available for creating voice-
       enabled applications, interfacing with other audio sources, and
       providing extensive application control over the recognition
     * Availability: SunSite archive at as well as on
       Catalyst CDware as both a runable demo and unlockable software.
     * Hardware Required: Sun SPARCstation with audio input. Noise
       canceling microphone recommended but not required.
     * Software Required:
          + Sun OS 4.1.2 with OpenWindows 3.0
          + or, Sun OS 4.1.3
          + or, Solaris 2.1 or Solaris 2.2
     * Misc: An equivilant MS-Windows product is described above.
     * Price: $495 U.S.
     * Contact: 
    Brantley Kelly
    Email: CIS: 75120,431
    FAX: 1-404-925-7924 Phone: 1-404-813-8030
    Command Corp. Inc, 3675 Crestwood Parkway, Duluth GA 30136, USA
    Phonetic Engine 400 (PE400) - Speech Systems, Inc.
     * Platform: PC
     * Description: Speaker independent, large vocabulary, continuous
       speech recognition for MS Windows or DOS.
     * Rough Cost: $1195 US dollars. Includes board, microphone,
       developer kit, documentation, 2 days of technical training and 90
       days of technical support.
     * Requirements: IBM AT class machine or better plus 5M disk space.
       Most processing is performed on-board (4M standard or 16M
     * Misc: Requires developer to provide a context-free grammar.
       Vocabulary size unknown (quotes from 500 - 2000 words per
       grammar), but dynamic grammar switching capabilities may increase
       the effective vocabulary size. Development system includes
       lower-level C,C++ library (VoiceLib), higher-level DLL (SPOT)
       callable from many languages, SPOT/VBX, a custom control for
       Visual Basic and Visual C++.
     * Contact: 
    Speech Systems, Inc.
    2945 Center Green Court South
    Boulder, CO 80301-2275, USA
    Tel: 303.938.1110 Fax: 303.938.1874
     * Platform: Sun SPARCstation
     * Description: Voice recognition and macro building package for
       Suns in the Openwindows 3.0 environment. Speaker dependent
       discrete speech recognition. Vocabularies can be associated to
       applications and the active vocabulary follows the application
       that has input focus. Macros can include mouse commands,
       keystrokes, Unix commands, sound, Openwindow actions and more. An
       evaluation copy is available by email.
     * Hardware: Microphone required (SunMicrophone is fine).
     * Cost: $US295
     * Contact: 
    Phone: 1-800-245-UNIX or 1-415-572-0200
    Fax: 1-415-572-1300
    Kurzweil Voice for Windows
     * Platform: MS Windows 3.1
     * Description: Kurzweil Voice for Windows is a dictation product
       enabling the user to create text and enter data by speaking to
       Windows-based applications. System is adaptive but requires no
       initial training. Users can choose either 30,000 or 60,000 word
       active vocabulary. Application command translation templates for
       popular Windows application such as WordPerfect, 1-2-3, Organizer,
     * Cost: US $995
     * Hardware: 486DX/33 or higher, 8 or 16 MB dedicated memory
       (depends on vocabulary, 30 MBs dedicated disk space, VGA or
       higher, Kurzweil-supplied microphone and DSP board.
     * Contact:
    Phone: 1-800-380-1234
    D6006 Voice Control Processor
     * Platform: ?
     * Description: ?
     * Contact: 
    DSP Telecommunications Inc.
    2855 Kifer Road, Suite 202, Santa Clara CA 95051, USA
    Speech Commander - Listen for Windows
     * Platform: ?
     * Description: ?
     * Contact: 
    Verbex Voice Systems
    1090 King Georges Post Rd., Bldg 107,
    Edison NJ 08837, USA
    Voice-Trek 2.0
     * Platform: ?
     * Description: ?
     * Contact: 
    Tardis Technology Inc., Voice Recognition Div.
    10321 Los Alamitos Blvd., Los Alamitos CA 90720
    Tel:(310)799-3355 Fax:(310)799-3360
    Visus SpeechKit
     * Platform: NeXT
     * Description: SpeechKit is based on SPHINX, a
       speaker-independent, 1000 word or so, continuous speech
       recognition system which allows you to incorporate speech
       recognition into your applications. You can design your vocabulary
       and grammars.
     * Contact: Visus - no address or phone provided. A possible
       contact is Robert Brennan at Carnegie Mellon University. email:
     * Platform: UNIX
     * Description: Speech recognition for the speaker independent
       TIMIT and Resource Management tasks. It uses recurrent networks to
       estimate phone probabilities and Markov models to find the most
       probable sequence of phones or words. The system is a snapshot of
       evolving research code. There is no documentation other than
       published research papers. The components are:
          + A preprocessor which implements many standard and many non-
            standard front end processing techniques.
          + A recurrent net recogniser and parameter files
          + Two Markov model based recognisers, one for phone recognition
            and one for word recognition
          + A dynamic programming scoring package The complete system
            performs competatively.
     * Cost: Free
     * Requirements: TIMIT and Resource Management databases
     * Contact: Tony Robinson:
     * Availability: by anonymous ftp
    Lotec Speech Recognition Package
     * Platform: Sun
     * Description: Public domain speech recognition software. Operates
       from input in Sun audio format (.au files) and outputs word
       hypotheses and time labelling data. The software includes programs
       to collect speech samples, a labeller, a "featurizer" which
       parameterises speech files, a word spotter and the recogniser. The
       software can perform real time recognition on a Sparc 10 for small
     * Requirements: Sun SPARC audio input and a "decent" microphone
       Sun multimedia demo software (in /usr/demo/SOUND) and X.
     * Availability: By anonymous ftp
     * Contact: Nigel Ward:
    Myers' Hidden Markov Model software
     * Description: Hidden Markov model software for automatic speech
       recognition. C++ code that implements a basic left-right hidden
       Markov model and corresponding Baum-Welch (ML) training algorithm.
       It is meant as an example of the HMM algorithms described by
       L.Rabiner and others. The code was built in order to learn how HMM
       systems work and we are now offering it to the net so that others
       can learn how to use HMMs for speech recognition. Keep in mind
       that ease of understanding was pit primary concern, not
       efficiency. The code can be used to build an experimental speech
       recognition systems using "train_hmm" and "test_hmm", and can be
       used in conjunction with written tutorials on HMMs to understand
       how they work.
     * Availability: By anonymous ftp from the comp.speech archive
       site. There are three files in the directory
   The files are
          + hmm.README
          + hmm-1.0.tar.Z
          + OR, hmm-1.0.tar.gz
   (Note: hmm-1.0.tar.Z and hmm-1.0.tar.gz compressed and GNU compressed
       versions of the same files)
     * Contact: Richard Myers: email
    Voice Command Line Interface
     * Platform: Amiga
     * Description: VCLI will execute CLI commands, ARexx commands, or
       ARexx scripts by voice command through your audio digitizer. VCLI
       allows you to launch multiple applications or control any program
       with an ARexx capability entirely by spoken voice command. VCLI is
       fully multitasking and will run in the background, continuously
       listening for your voice commands even while other programs are
       running. Documentation is provided in AmigaGuide format. VCLI 6.0
       runs under either Amiga DOS 2.0 or 3.0.
     * Cost: Free?
     * Requirements: Supports the DSS8, PerfectSound 3, Sound Master,
       Sound Magic, and Generic audio digitizers.
     * Availability: by ftp from in the file
       systems/amiga/incoming/audio/VCLI60.lha and from as the file pub/aminet/util/misc/VCLI60.lha
     * Contact: Author's email is
    DATAVOX - French
     * Platform: PC
     * Description: Continuous speech - speaker independent or
     * Rough Cost: ?
     * Requirements: 2 PC format boards (RdF1000 and TdS 96/25) and an
       A/D - D/A module (ASA116)
     * Misc: Application software may dialog with DATAVOX through 2
       types of interfaces :
          + Keyboard overlay: The application software may be used with
            any PC compatible package. No specific adaptation is
            necessary, you only need to define your configuration with
            the application software.
          + C library: Allows a user-written program to drive the
            recognition system.
   DATAVOX is based on the AMADEUS speech recognition software developed
       at LIMSI. It provides
          + Continuous speech recognition with 500 words speaker
            dependent, 50 words speaker independent (custom-made
          + Grammar of the application language (syntax acquisition,
            verification and simplification software).
          + Large vocabulary : DATAVOX can recognize vocabularies of
            several thousand words as long as there are no more than 500
            words in the active vocabulary at any given node. It takes
            less than 1 second to change syntax and vocabulary.
          + Training controlled by the system (use of co-articulation
          + Response time less than 500 ms for any phrase length.
          + Synthetis (ADPCM) can be heard simultaneously while
            recognition is being carried out.
     * Contact:
    Le Chene rond, 91570 Bievres, France
    Fax: 33 1 69 41 24 30
    Voice: 33 1 69 41 15 04
     * Platform: Centris 650, 660AV. Quadra 650, 660AV, 700,800, 840AV,
       900, 950.
     * Description: Speaker dependent/adaptive system requiring words
       to be separated by short pauses.
     * Vocabulary: 30,000 at any one time, automatically selected from
       120,000-word dictionary.
     * Cost: US$2,495; non-AV machines need an audio board will cost
       about US$300.
     * Requirements: Minimum of 16M of ram and System 7.0.
     * Contact:
    Articulate Systems
    600 W. Cummings Park, Suite 4500
    Woburn, MA 01801
    Ph: (617) 935-5656 Fax: (617) 935-0490.
    ICSS system from IBM
     * Description: A large vocabulary, speaker independent, continuous
       speech system which runs under Windows, OS/2, and AIX.
     * Requirements: Soundboard (e.g. Soundblaster)
     * Price: $US319
     * Contact: 
    A&G Graphics Interface
    ICSS Reseller
    51 Gore Street, Cambridge, MA, 02139, USA
    (617) 492-0120
    Custom Voice(TM) by A&G Graphics Interface
     * Description: Speech recognition custom control for Visual Basic,
       Visual C++, Borland C++, and other development platforms that
       support *.VBX. Provides an engine/proprietary independent
       development platform for speech recognition. Currently supports
       ICSS, but should soon support other platforms. Includes a grammar
       debugger and parser APIs to parse spoken speech into useful data
     * Requirements: Visual Basic or any development platform that
       supports VBX.
     * Price: $US495 or $695 bundled with ICSS.
     * Contact: 
    A&G Graphics Interface
    51 Gore Street, Cambridge, MA, 02139, USA
    (617) 492-0120
    Creative VoiceAssist
     * Platform: PC (?)
     * Price: $US99.95
     * Contact:
    Creative Labs
    Ph: 1-800-998-5227

Andrew Hunt
Speech Technology Research Group		Ph:  61-2-351 4509
Dept. of Electrical Engineering			Fax: 61-2-351 3847
University of Sydney, NSW, 2006, Australia	email: