Open al terminates game with NSException on iOS - ios

Question

when i play my sound it says there is something wrong with the code but i cannot see what it is. The game runs fine until i try to play the sound which is when it terminates with uncaught exception of type NSException. It is not the best example of Open Al but can anybody see what is wrong with it?
- (id)init
{
self = [super init];
if (self)
{
openALDevice = alcOpenDevice(NULL);
openALContext = alcCreateContext(openALDevice, NULL);
alcMakeContextCurrent(openALContext);
}
return self;
}
-(void)playSound {
NSUInteger sourceID;
alGenSources(1, &sourceID);
NSString *audioFilePath = [[NSBundle mainBundle] pathForResource:#"flyby" ofType:#"caf"];
NSURL *audioFileURL = [NSURL fileURLWithPath:audioFilePath];
AudioFileID afid;
OSStatus openAudioFileResult = AudioFileOpenURL((__bridge CFURLRef)audioFileURL, kAudioFileReadPermission, 0, &afid);
if (0 != openAudioFileResult)
{
NSLog(#"An error occurred when attempting to open the audio file %#: %ld", audioFilePath, openAudioFileResult);
return;
}
UInt64 audioDataByteCount = 0;
UInt32 propertySize = sizeof(audioDataByteCount);
OSStatus getSizeResult = AudioFileGetProperty(afid, kAudioFilePropertyAudioDataByteCount, &propertySize, &audioDataByteCount);
if (0 != getSizeResult)
{
NSLog(#"An error occurred when attempting to determine the size of audio file %#: %ld", audioFilePath, getSizeResult);
}
UInt32 bytesRead = (UInt32)audioDataByteCount;
void *audioData = malloc(bytesRead);
OSStatus readBytesResult = AudioFileReadBytes(afid, false, 0, &bytesRead, audioData);
if (0 != readBytesResult)
{
NSLog(#"An error occurred when attempting to read data from audio file %#: %ld", audioFilePath, readBytesResult);
}
AudioFileClose(afid);
ALuint outputBuffer;
alGenBuffers(1, &outputBuffer);
alBufferData(outputBuffer, AL_FORMAT_STEREO16, audioData, bytesRead, 44100);
if (audioData)
{
free(audioData);
audioData = NULL;
}
alSourcef(sourceID, AL_PITCH, 1.0f);
alSourcef(sourceID, AL_GAIN, 1.0f);
alSourcei(sourceID, AL_BUFFER, outputBuffer);
alSourcePlay(sourceID);
}