Meanings of low cough in English

Suddenly I thought I heard a low cough a short distance away.

As if in answer, the car gave a low cough.

Really, really bad. She let out a low cough.

At intervals they uttered a strange sound, like the low cough of a person in consumption.

She heard a low cough.

He hadn't met a soul yet, but he'd stopped now because he'd heard a low cough from the dimness ahead.

A low cough sounded down the corridor and they quickly desisted from their task and retired to their room while a maid passed by.

The sound of her low cough rang in his ears, and he rather heightened than removed the picture which haunted Mainwaring,-Susanstricken, dying, broken-hearted!

"She's my girlfri- "Hisvoice stumbled on the word, and he tried to cover it with a low cough.