Old men sleep lightly; m. Gillenormand's chamber adjoined the drawing-room, and in spite of all the precautions that had been taken, the noise had awakened him.

老年人的睡眠，容易惊醒；吉诺曼先生的卧室紧连着客厅，尽管大家很小心，仍有声音把他惊醒了。

youdao

She sleeps lightly.; She is easily roused from sleep.

她睡觉很惊醒。

《新英汉大辞典》

Normally I'd only be able to sleep very lightly in such a situation, unless I was extremely tired.

我很惊讶我现在可以在车上小睡，以前我是没办法在这种环境中睡觉的，除非我真的是累极了。

youdao

Dr Melissa Hack, chairman of the British Sleep Society, said that women generally tended to sleep more lightly than men, and so often expected they were not going to sleep well.

BBC: NEWS | Health | Women 'too meek' over men snoring