What you're really hearing there are the person's heart valves opening and closing.

你真正听到的是人的心脏瓣膜打开和关闭。

Most people believe that the cat's brain signals the laryngeal muscles to vibrate and function like a valve, opening and closing the space between the vocal cords.

大多数人认为，猫的大脑会向喉部肌肉发出信号，使其振动并像阀门一样发挥作用，打开和关闭声带之间的空间。

Concentric hypertrophy leading to diastolic failure can also be caused by aortic stenosis, which is a narrowing of the aortic valve opening, as well by hypertrophic cardiomyopathy, an abnormal ventricular wall thickening often from a genetic cause.

导致舒张性心衰的向心性肥大，也可能由主动脉瓣狭窄（即主动脉瓣开口变窄）造成，也可能由肥厚型心肌病（一种遗传性异常心室壁增厚）引起。