AVAudioSession delegate deprecated in softmodemterminal

AVAudioSession delegate deprecated in softmodemterminal

Here's the source code of softmodemterminal
https://code.google.com/p/arms22/downloads/detail?name=SoftModemTerminal-004.zip&can=2&q=
..
I have tried google so many times but find no proper answer , any could
help me? Thanks
AVAudioSession *session = [AVAudioSession sharedInstance];
session.delegate = self;
if(session.inputIsAvailable){
[session setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
}else{
[session setCategory:AVAudioSessionCategoryPlayback error:nil];
}
[session setActive:YES error:nil];
[session setPreferredIOBufferDuration:0.023220 error:nil];
recognizer = [[FSKRecognizer alloc] init];
[recognizer addReceiver:mainViewController];
generator = [[FSKSerialGenerator alloc] init];
[generator play];
analyzer = [[AudioSignalAnalyzer alloc] init];
[analyzer addRecognizer:recognizer];
if(session.inputIsAvailable){
[analyzer record];
}