The reason Pirripli’s code does not work is that the simulator does not support the test and the code does not check for errors. Corrected code would look like:
CFStringRef state = nil;
UInt32 propertySize = sizeof(CFStringRef);
AudioSessionInitialize(NULL, NULL, NULL, NULL);
OSStatus status = AudioSessionGetProperty(kAudioSessionProperty_AudioRoute, &propertySize, &state);
if (status == kAudioSessionNoError)
{
return (CFStringGetLength(state) == 0); // YES = silent
}
return NO;