For some the sound could make sleep harder, but for others, the steady beat of the ticking, or the quiet hum of an electric motor in a fan can be very peaceful.

有些东西发出的声音令你很难入睡，但有些东西是固定行走或敲打的，风扇有规律的转动的声音听起来很和平。

youdao

Today, the Usambara Mountains are a quiet, peaceful corner of northeastern Tanzania, rarely visited by outsiders -- invading or otherwise.

BBC: A tranquil slice of Tanzania