问题
I am using Apple's SpeakHere example in my project. I can record voice and play without problems..
The problem occurs when I change the view controller where I am using AVAudioPlayer to play recorded voices.. If I go back to SpeakHereViewController to record once again, then it keeps saying "ERROR: metering failed". Why is it happening? Thanks in advance.
来源：https://stackoverflow.com/questions/17691616/speakhere-voice-recorder-fails-after-avaudioplayer-in-ios