Delay when activating AVAudioRecorder

Question

I am facing a strange problem with AVAudioRecorder. In my application i need to record audio and play it. I am creating my player as :

if(recorder)
{
if(recorder.recording)
[recorder stop];
[recorder release];
recorder = nil;
}

NSString * filePath = [NSHomeDirectory() stringByAppendingPathComponent: [NSString stringWithFormat:@"Documents/%@.caf",songTitle]];
        NSDictionary *recordSettings = [[NSDictionary alloc] initWithObjectsAndKeys:
                                        [NSNumber numberWithFloat: 44100.0],AVSampleRateKey,
                                        [NSNumber numberWithInt: kAudioFormatAppleIMA4],AVFormatIDKey,
                                        [NSNumber numberWithInt: 1], AVNumberOfChannelsKey,
                                        [NSNumber numberWithInt: AVAudioQualityMax],AVEncoderAudioQualityKey,nil];
        recorder = [[AVAudioRecorder alloc] initWithURL: [NSURL fileURLWithPath:filePath] settings: recordSettings error: nil];
        recorder.delegate = self;
if ([recorder prepareToRecord] == YES){
                [recorder record];

I am releasing and creating player every time I press record button. But the problem is that, AVAudiorecorder is taking some time before starting to record, and so if I press record button multiple times continuously, my application freezes for some time.

The same code works fine without any problem when headphones are connected to device...there is no delay in recording, and the app doesn't freeze even if I press record button multiple times.

Answer 1

Got the solution. I just added the code

AVAudioSession *audioSession = [AVAudioSession sharedInstance];
        NSError *err = nil;
        [audioSession setCategory :AVAudioSessionCategoryPlayAndRecord error:&err];
        if(err){
            NSLog(@"audioSession: %@ %d %@", [err domain], [err code], [[err userInfo] description]);
            return;
        }
        err = nil;
        [audioSession setActive:YES error:&err];
        if(err){
            NSLog(@"audioSession: %@ %d %@", [err domain], [err code], [[err userInfo] description]);
            return;
        }

and it is now working fine. However i want to know what difference does this piece of code made? And why it was like that my application was working fine with headphones connected but freezed without them.?