当你紧紧地闭上眼睛或以某种方式活动下巴肌肉之时,都会出现一种怪异的声音,它听起来就像一阵低沉的隆隆声或者正在飞过的飞机所发出的声音。那么,这个声音到底是怎么回事呢?它是否有害呢?紧闭眼睛时听到的声音其实是由耳朵中的鼓膜张肌所产生的,其主要功能是抑制自己咀嚼时产生的声音。这种肌肉可以自主收缩产生振动,从而发出了这种奇怪的声音。慢缩肌纤维每秒能产生10至30次收缩,而快缩肌纤维每秒则能产生30至70次收缩,这些肌肉收缩 As you close your eyes tightly or somehow move your chin muscles, a weird sound can appear that sounds like a deep rumbling or the sound of a flying aircraft. So what’s going on with the sound? Is it harmful? The sound that is heard when you close your eyes is actually produced by the tympanic membrane muscle in your ears, whose main function is to suppress the sound that is generated when you chew. This kind of muscle can spontaneously contract and vibrate, giving this weird noise. Slow-contracting fibers produce 10 to 30 contractions per second, whereas fast-contracting fibers produce 30 to 70 contractions per second. These muscles contract