iOS sound playback latency

[josecastelo]

I am willing to develop a virtual percussion instrument for iPhone/iPad.
I need very low latency for sound playback (the time between the user taps the screen and when the sound actually sounds), in order to have a "real" usable musical instrument.
As the iOS exporter module for MMF2 uses Open AL as the sound engine (for short sounds), it may give, in theory, low or very low latency.
I have tried other platforms (Gamesalad, Appcelerator or Corona) with no luck.
Can anyone confirm me that point? (i haven´t bought the iOS exporter yet, and no demo is available to test it by myself).

[Keith]

If you use WAV files the latency appears to be undetectable. For an instrument you need about 10-15 ms or the user will notice and so far I have had nothing appear to break this threshold. I am however not using more than a few sounds at a time.

If you use MP3s however you will have problems since the iPhone only can decode a single MP3 stream into a buffer at a time from what I understand.

[Jeff]

If you put together a little test app I would test it out and see if it worked OK.

[josecastelo]

Thanks Jeff,
I have included a simple app to test the latency and playability in iOS.