How can I reduce the speed of sound playing on Iphone using Objective C

I have an开发者_如何学Go mp3 that I want to play slowly without altering the pitch. Is there a way to do it? I can convert into other forms, if I can do it in other forms. This is for a iPhone app that I am developing.

Thanks

A time-pitch modification/stretching algorithm or library could be used for this. You could develop some DSP analysis/resynthesis code for a phase vocoder, a PSOLA pitch corrector, or use a commecial library such as Dirac.

See the stackoverflow question: iPhone voice changer for some other answers to a similar question.