early homo, they say, might have based his first words either on the noises he heard, like the splash of falling water or the thud of a rock smashing into a skull;

他们声称，早期人类的第一个词也许要么基于他所听到的噪音，像是溅水的声音，或者岩石敲击头骨的声音；

youdao

A sharp crack might remain fairly sharp in granite, but degenerate into a dull thud in sand.

在花岗岩中尖锐的破裂声可以保留相当的强度，而在砂岩中则易变成低沉的轰响。

youdao

The occasional thud of mortar or reports of a Burmese helicopter gunship sent them scurrying into their bunkers throughout Saturday, he said.

BBC: Burma ceasefire 'holds' in rebel-held Kachin areas