//录音设置
NSDictionary *RecordParam = [[NSDictionaryalloc] initWithObjectsAndKeys:
[NSNumber numberWithFloat: 8000.0],AVSampleRateKey, //采样率
[NSNumber numberWithInt: kAudioFormatLinearPCM],AVFormatIDKey,
[NSNumber numberWithInt:16],AVLinearPCMBitDepthKey,//采样位数默认 16
[NSNumber numberWithInt: 1], AVNumberOfChannelsKey,//通道的数目
[NSNumber numberWithInt: AVAudioQualityMedium],AVEncoderAudioQualityKey,//音频编码质量
nil];
NSString *DocmentPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES) objectAtIndex:0];
NSURL *url = [NSURLURLWithString:[DocmentPath stringByAppendingString:@"/luyin.wav"]];
urlPlay = url;
NSError *error;
//初始化
recorder = [[AVAudioRecorder alloc]initWithURL:url settings:RecordParam error:&error];
//开启音量检测
recorder.meteringEnabled = YES;
recorder.delegate = self;