Meanings of strained senses in English

All at once to her strained senses there seemed to flash some apprehension of a coming danger.

Ten thousand dead, yet strangely alive-hisstrained senses could feel their vigilance, their stillness a blind over that horrible alertness.

It might have been made by some woodland creature, but to his strained senses every sound, however slight, suggested a possible clue.

Jim listened, and presently his strained senses caught a faint sound like the throbbing of a tiny engine somewhere away in the darkness.

To his strained senses there seemed to be another just measurable pause before Anna said, looking gaily about the little group: Has Owen introduced you?

"Really, madam, I regret to seem hard;" and the polished courtesy of the cold, harsh voice fell with heavy weight upon her strained senses.