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.
SetSpeechPitch
You can use the SetSpeechPitch function to set the speech pitch on a designated speech channel.
FUNCTION SetSpeechPitch (chan: SpeechChannel; pitch: Fixed) : OSErr;
chan
- The speech channel whose pitch you wish to set.
pitch
- The new pitch for the speech channel, expressed as a fixed-point frequency value.
DESCRIPTION
TheSetSpeechPitch
function changes the current speech pitch on the speech channel specified by thechan
parameter to the pitch specified by thepitch
parameter. Typical voice frequencies range from around 90 hertz for a low-pitched male voice to perhaps 300 hertz for a high-pitched child's voice. These frequencies correspond to approximate pitch values in the ranges of 30.000 to 40.000 and 55.000 to 65.000, respectively. For information about the mathematical relationship between pitches and frequencies expressed in hertz, see "Speech Attributes" beginning on page 4-6. Although fixed-point values allow you to specify a wide range of pitches, not all synthesizers will support the full range of pitches. If your application specifies a pitch that a synthesizer cannot handle, it may adjust the pitch to fit within an acceptable range.SPECIAL CONSIDERATIONS
You can call theSetSpeechPitch
function at interrupt time.ASSEMBLY-LANGUAGE INFORMATION
The trap macro and routine selector for theSetSpeechPitch
function are
Trap macro Selector _SoundDispatch
$044C000C RESULT CODES
noErr 0 No error invalidComponentID -3000 Speech channel is uninitialized or bad