The whistle was inaudible to the human ear.

这种啸声人耳听不到。

《牛津词典》

The noise is barely detectable by the human ear.

这种噪音人的耳朵几乎是察觉不到的。

《牛津词典》

The sound is virtually undetectable to the human ear.

这声音实际上是人耳难以听得到的。

《牛津词典》

The body, the mouse, or the human, or any organism already shows us how to make an ear.

身体，老鼠，人以及其他一些组织,业已向我们展示了耳朵的发育。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

He said "close inspection" led him to believe it was "definitely a human ear".

BBC: Ben Jackson-Smith with his girlfriend and Kas

The man who found a human ear while walking a dog in an Aylesbury graveyard says he is in "disbelief".

BBC: Ben Jackson-Smith with his girlfriend and Kas

Dogs are capable of hearing high-frequency sounds imperceptible to the human ear.

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