If you don't need much precision and you want to stick with AVAudioPlayer, this is one option:
- (void)playAtTime:(NSTimeInterval)time withDuration:(NSTimeInterval)duration {
NSTimeInterval shortStartDelay = 0.01;
NSTimeInterval now = player.deviceCurrentTime;
[self.audioPlayer playAtTime:now + shortStartDelay];
self.stopTimer = [NSTimer scheduledTimerWithTimeInterval:shortStartDelay + duration
target:self
selector:@selector(stopPlaying:)
userInfo:nil
repeats:NO];
}
- (void)stopPlaying:(NSTimer *)theTimer {
[self.audioPlayer pause];
}
Bear in mind that stopTimer will fire on the thread's run loop, so there will be some variability in how long the audio plays, depending on what else the app is doing at the time. If you need a higher level of precision, consider using AVPlayer instead of AVAudioPlayer. AVPlayer plays AVPlayerItem objects, which let you specify a forwardPlaybackEndTime.