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Inside Macintosh: Sound /
Chapter 4 - Speech Manager / Speech Manager Reference
Speech Manager Routines / Changing Speech Attributes


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Important: Inside Macintosh: Sound is deprecated as of Mac OS X v10.5. For new audio development in Mac OS X, use Core Audio. See the Audio page in the ADC Reference Library.

SetSpeechRate

You can set the speech rate of a designated speech channel with the SetSpeechRate function.

FUNCTION SetSpeechRate (chan: SpeechChannel; rate: Fixed): OSErr;
chan
The speech channel whose rate you wish to set.
rate
The new speech rate for the speech channel, expressed as a fixed-point, words-per-minute value.
DESCRIPTION
The SetSpeechRate function adjusts the speech rate on the speech channel specified by the chan parameter to the rate specified by the rate parameter. As a general rule, typical speaking rates range from around 150 words per minute to around 180 words per minute. It is important to keep in mind, however, that users will differ greatly in their ability to understand synthesized speech at a particular rate based upon their level of experience listening to the voice and their ability to anticipate the types of utterances they will encounter.

SPECIAL CONSIDERATIONS
You can call the SetSpeechRate function at interrupt time.

ASSEMBLY-LANGUAGE INFORMATION
The trap macro and routine selector for the SetSpeechRate function are
Trap macroSelector
_SoundDispatch$0444000C

RESULT CODES
noErr0No error
invalidComponentID-3000Speech channel is uninitialized or bad

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© Apple Computer, Inc.
2 JUL 1996