These three signals are often heard "fighting" each other out across lower Michigan.

The signal could hardly be heard; but Harry expected it.

Its signal can be heard most clearly in the counties surrounding Nashville.

The mysterious signal is heard over every channel throughout the base.

No intercom out here where signals could be heard by the enemy.

The signal was heard, for immediately an answering shout came from the shore.

Such signals can be heard many days' sailing away.

The signal was heard, and the boat started leisurely from the pier.

The signal must now be seen and heard everywhere.

Over the years its powerful 50,000-watt signal could clearly be heard throughout much of California.