cocoaModem Text-to-Speech
(Mac OS X)


   CocoaModem is a Mac OS X modem program for the amateur radio digital modes, such as PSK31 and RTTY. The user interface has features specifically for blind and vision-impaired hams. This article describes the text-to-speech features in cocoaModem, which include:

     • Automatic text-to-speech.
     • Customized ham radio vocabulary.
     • User-defined vocabulary.
     • Automatic spelling of call signs.
     • Spelling mode for copying weak signals.

   The Incremental Speech and Voice Assist options augment the easy-to-use VoiceOver screen reader built into Mac OS X.

   The program is described in a separate article on the accessibility of the user interface.

Automatic Text-to-Speech

   CocoaModem has an incremental (word-by-word) text-to-speech option that speaks a new word when it is received or transmitted. The VoiceOver screen reader is also available to read text, but Incremental Speech works automatically—much easier than typing VoiceOver commands to select and read each received message.

   An automatic spelling option (letter-by-letter) is useful for copying weak signals with "noise characters" in the text.

   The quality of the text-to-speech is excellent, and W7AY has added an extensive list of substitutions that make spoken ham messages easier to understand. For example:  Q-signals, such as QRZ, are spoken as separate letters instead of a word. Common ham shorthand is converted into English words—"de" is spoken as "from," and "pse k" as "please go ahead."

   The cocoaModem vocabulary is also customizable. You can create an Enunciate.txt file of preferred pronunciations.

   Incremental Speech automatically detects call signs (mixed letters and digits) and spells them. Without this feature the suffix of some call signs would be pronounced as a word.

Sound Cards

   Two sound cards are required for digital mode text-to-speech—one for signal processing and another (typically the PC sound card or chipset) for speech. This arrangement prevents the output of the speech synthesizer from being transmitted on the band.

Examples of QSO's

   Two examples of QSO's demonstrate how easy it is to use cocoaModem text-to-speech.

   A video by W1BLS demonstrates cocoaModem text-to-speech. The page also has a link to an MP4 version for Mac users.

For More Information

   • Accessibility section in the online User's Manual.
   • PSK31 Operating Notes from a Blind Ham.
   • cocoaModem Accessibility article.


   CocoaModem has an incremental text-to-speech option that automatically speaks each word as it is received or transmitted. It is much easier to use for digital text modes than a screen reader. The speech quality is excellent, and W7AY has added an extensive list of substitutions that convert ham abbreviations into natural language.


   Thanks to W7AY for answering questions and for including accessibility features in cocoaModem.


Author Information

   Peter DeNeef, AE7PD, is an Extra Class amateur radio operator in the U.S. This Web site has no ads or conflicts of interest.
Email:  HamRadioAndVision "at" gmail "dot" com.

rev. 12/29/2013

Mac OS X Programs on HamRadioAndVision

HamRadioAndVision Table of Contents