220赫兹的声音听起来不正确

Question

我有以下Objective-C代码生成220hz音调，但是，它听起来不像其他220hz音调，例如维基百科在这里有220音：https://en.wikipedia.org/wiki/File:220_Hz_sine_wave.ogg听起来非常低，我的声音听起来比较高......任何想法？

- (void)render:(AVAudioPCMBuffer *)bufferInput frequency:(float)frequency amplitude:(float)amplitude
{
    const int channels = 2;
    int inNumberFrames = bufferInput.frameLength;
    float *const *floatChannelData = bufferInput.floatChannelData;

    for (int i = 0; i < inNumberFrames ; i ++) {
        float theta = frequency * i * 2.0 * M_PI / 44100;
        float value = sinf(theta);
        for (int channelNumber = 0; channelNumber < channels ; channelNumber++) {
            float * const channelBuffer = floatChannelData[channelNumber];
            channelBuffer[i] = value * amplitude;
        }
    }
}