Unity c# 麦克风输入音量

float LevelMax()
    {
        float levelMax = 0;
        float[] waveData = new float[_sampleWindow];
        int micPosition = Microphone.GetPosition (null) - (_sampleWindow + 1);
        if (micPosition < 0) {
            return 0;
        }
        _clipRecord.GetData (waveData, micPosition);
        for (int i = 0; i < _sampleWindow; ++i) {
            float wavePeak = waveData [i] * waveData [i];
            if (levelMax < wavePeak) {
                levelMax = wavePeak;
            }
        }
        return levelMax;
    }