He says the payback is simple.

VOA: special.2010.07.16

I don't know whether it's easier for gentlemen or not because our voices are sort of in the bass, but maybe this is payback time since ladies are always singing the melody.

我不知道是否男人更容易唱出低声部，因为我们的嗓音本来就低，不过这也可能是女士们报复的时间到了，她们总是得唱旋律。

耶鲁公开课 - 聆听音乐课程节选