All eyes were to the front, and ears alerted to imminent commands.

Any new thing or strange action will bring his head up and his ears alert.

He moved slowly, checking each step and looking constantly around, his ears alert for any slight sounds that might tip him off.

Fred goes into the adjoining bathroom, ears alert for any movement behind him.

He must have sensed my hesitation, his ears alert for any change in the note of the engine.

Nothing moved about the travelers as they marched in silence, their eyes and ears alert to anything out of the ordinary.

She moved into the room, swinging right, then left, eyes sharp, ears alert.

He looked down, perplexed, suspicious, his ears alert for the slightest sound without.

So I lived through those hours, startled at every sound, ears alert for arrivals.

Then they heard - their ears alert for the slightest changes in the grind of the traffic - a car slowing just behind them.