话筒（麦克风） are used to 捕捉 声音 They 测 共鸣 in the air caused by 声音 波 and convert these into 电子 信号 These 电子 信号 are then passed on to be 储存 in the 过程 of 录音 or fed to 扬声器 which convert the 电子 信号 back into soundwave 共鸣

There are many different 种类 of 话筒（麦克风） which come in many 形状 and sizes and they often 使用 slightly different 技术 Powered ‘condenser microphones’ and unpowered ‘dynamic microphones’ are the most common 种类 With condenser 话筒（麦克风） being the more 敏感 of the two

Special 工具 are also available to 录制 声音 that travel through liquids and through solids Hydrophones can 录制 声音 that travel through liquids and are used to 录制 underwater 声音 While contact 话筒（麦克风） are able to 测 声波 that 通过 through 固体 对象