What does the writer describe as an 'amusing old-fashioned source of noise' ?

作者是怎样描述一处“引人发笑的老式噪音源”的？

The survey revealed a large number of sources of noise that we really dislike.

这个调查揭示了我们所不喜欢的大量的噪间的来源。

The noise pollution survey revealed a rather surprising and possibly amusing old fashioned source of noise.

这个有关噪音的污染调查还揭示了一种出人意外同时可能会引人发笑的老式噪音源。

However, we must ponder on whether kids are the only source of noise in trains.

然而，我们必须思考孩子是否是火车上唯一的噪音来源。