很可能你录音时AVAudioSession设为了AVAudioSessionCategoryPlayAndRecord,录音结束时没有设回来
AudioSessionCategoryPlayAndRecord是用听筒播放,所以声音会很小
let session = AVAudioSession.sharedInstance()
do {
try session.setActive(true)
} catch let error as NSError {
print("无法访问您的麦克风")
return
}
if session.category != AVAudioSessionCategoryPlayback {
try session.setCategory(AVAudioSessionCategoryPlayback)
}