1.扬声器模式:
NSError *error;
[[AVAudioSession sharedInstance] overrideOutputAudioPort:AVAudioSessionPortOverrideSpeaker error:&error];
NSLog(@"error:%@",error);
2.听筒模式:
NSError *error;
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:&error];
NSLog(@"error:%@",error);
原文:http://www.cnblogs.com/yyt-hehe-yyt/p/7253970.html