Easy to use class that creates audio file with silence
To make it work you should just call makeSilenceWithLength:atPath:
with silence duration and path.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *file = [documentsDirectory stringByAppendingPathComponent: @"audio.m4a"];
[SilenceMaker makeSilenceWithLength:60 * 60 * 23.5 atPath:file];
In code you can see a commented second version with kAudioFormatiLBC. iLBC files has a very small size. But second version of code is don't work now. See Apple sample as a tutorial.
Improvements and contributions are always welcome.