AVAudioSessionRecordPermission permission = [[AVAudioSession sharedInstance] recordPermission];
     //判断是否授权
    if (AVAudioSessionRecordPermissionUndetermined == permission) {
        [[AVAudioSession sharedInstance] requestRecordPermission:^(BOOL granted) {
            //授权回调操作
        }];
    } else {
        //用户没有同意授权
    }

    //首先设置录音模式
    AVAudioSession *session = [AVAudioSession sharedInstance];
            NSError *sessionError;
            /*
             AVAudioSessionCategoryPlayAndRecord :录制和播放
             AVAudioSessionCategoryAmbient       :用于非以语音为主的应用,随着静音键和屏幕关闭而静音.
             AVAudioSessionCategorySoloAmbient   :类似AVAudioSessionCategoryAmbient不同之处在于它会中止其它应用播放声音。
             AVAudioSessionCategoryPlayback      :用于以语音为主的应用,不会随着静音键和屏幕关闭而静音.可在后台播放声音
             AVAudioSessionCategoryRecord        :用于需要录音的应用,除了来电铃声,闹钟或日历提醒之外的其它系统声音都不会被播放,只提供单纯录音功能.
             */
            [session setCategory:AVAudioSessionCategoryPlayAndRecord error:&sessionError];
            [session setActive:YES error:nil];
            // 录音参数
            NSDictionary *setting = [NSDictionary dictionaryWithObjectsAndKeys:
                                     [NSNumber numberWithInt:kAudioFormatMPEG4AAC], AVFormatIDKey,// 编码格式
                                     [NSNumber numberWithFloat:8000], AVSampleRateKey, //采样率
                                     [NSNumber numberWithInt:1], AVNumberOfChannelsKey, //通道数
                                     [NSNumber numberWithInt:16], AVLinearPCMBitDepthKey,  //采样位数(PCM专属)
                                     [NSNumber numberWithBool:NO], AVLinearPCMIsNonInterleaved,  //是否允许音频交叉(PCM专属)
                                     [NSNumber numberWithBool:NO],AVLinearPCMIsFloatKey,  //采样信号是否是浮点数(PCM专属)
                                     [NSNumber numberWithBool:NO], AVLinearPCMIsBigEndianKey,  //是否是大端存储模式(PCM专属)
                                     [NSNumber numberWithInt:AVAudioQualityMax], AVEncoderAudioQualityKey,  //音质
                                     nil];
            NSString *filePath = @"";//设置录音文件的存储路径
            self.recorder = [[AVAudioRecorder alloc] initWithURL:[NSURL URLWithString:filePath] settings:setting error:nil];
            self.recorder.delegate = self;
            //开启音频测量
            self.recorder.meteringEnabled = YES;
            [self.recorder prepareToRecord];
            [self.recorder record];    

//结束播放   
 if (self.recorder != nil) {
      [self.recorder stop];
 }

- (void)audioRecorderDidFinishRecording:(AVAudioRecorder *)recorder successfully:(BOOL)flag
{
   //录音技术操作

    //录音模式结束后需要将模式调整回来
    AVAudioSession *audioSession = [AVAudioSession sharedInstance];
    [audioSession setCategory:AVAudioSessionCategoryPlayback  error:nil];
}

- (void)audioRecorderEncodeErrorDidOccur:(AVAudioRecorder *)recorder error:(NSError * __nullable)error
{
   //录音失败调用
}