2月20日，正在菲律宾南莱特省泥石流灾区参加救援行动的美国官员说，由美国和马来西亚搜救队伍带来的地震探测仪和声音探测器，探测到了地下扒土和有节奏性的轻拍声。虽然救援人员目前无法确定这是幸存者发出的求救声，或是松软泥土移位的声音，但声音探测器毕竟说明被埋在泥中的师生有生还的可能。

请看《中国日报》相关报道：Rescue workers refused to give up hope of finding survivors in an elementary school buried by up to 100 feet of mud, digging into the night Monday after detecting what the provincial governor called "signs of life."

Sounds of scratching and a rhythmic tapping were picked up by seismic sensors andsound-detection gearbrought in by US and Malaysian forces.

报道中的sound-detection gear就是给救援工作带来希望的"声音探测器"。就这个合成词本身来讲并不难，今天主要谈谈sound在作为"探测"时的其它用法。Sound作动词时有"测探…的深度"之意，如：The expedition team is sounding the distance to the bottom and to the ice overhead（探险队员正在探测从水底到顶上冰块的距离）。

由此，sound衍生出"试探、探询"的意思，如：She listened to their conversation and tried to sound them as to their real intention（她倾听着她们的谈话，试图探听出他们的真实意图）。这时，sound常和out连用，如：The mayor sounded out the experts' views on the question of environmental pollution（市长征询专家们对环境污染的意见）。