1.   It emits a piercing tone when the number reaches a danger zone.

2.   Some people also turned up the volume so they could hear the piercing audio tone.

3.   Oliveira draws from all of them a lavishly piercing tone that vibrates from fingers whose warm, generous touch is powered by precision technique.

4.   The origins of yodeling are shrouded in antiquity, but its often piercing tones carry long distances and can help lone mountaineers locate each other.