iPhone voice changer

Question

I am developing an iphone app, which records user voice and change it into a female voice like (TALKING TOM and iHOBO). I am new to audio manipulation. Please tell me which api is required to do this? Can i implement this feature using iphone sdk apis? Is there any open source to implement this feature? Is there any tutorial regrading this?

Thanks in Advace

Answer 1

There are no built-in iOS APIs that will do independent time-pitch modification.

There is open source code that implements time-pitch stretching in Audacity, but I don't know whether this code has been ported to iOS. Same with SoundTouch.

There is a Time-Pitch Stretch Tutorial on the DSP Dimensions site.

Update: In late 2012, the kAudioUnitSubType_NewTimePitch Audio Unit was included with and built into the release of iOS 6, so you can now implement (independant time-pitch modification) voice changing using iOS APIs. See Apple's developer documentation for details.

Answer 2

Take a look at Dirac. It’s free of charge, though not free software.

Answer 3

the great link to download the sample code that provides all your needs,here also refer here for gaining more knowledge regarding your question.

In the init method of the Sample Code of HelloWorldLayer.mm ,u can see three float values as

time      = 0.7;  
pitch     = 0.8;
formant   = pow(2., 0./12.);

just adjust the pitch value to 1.9,it would be really a nice cat sound!!!