Research suggests that cats can purr for various reasons, using the soft rumble as a way of communicating and as a form of self-soothing or even healing.

研究表明，猫发出呼噜声有多种原因，它们用这种轻柔的声音交流或者用来自我疗愈，甚至疗伤。

Kittens are born blind and deaf, remaining so until they are around two weeks old. However, they begin purring after just a few days, primarily to let their mothers know where they are, and to attract their attention at feeding time.

小猫出生时看不见也听不到，这种状态要持续大约两周时间。然而它们出生几天后就会开始发出呼噜声，这主要是为了让母猫知道它们在哪里，并在喂食时引起母猫的注意。

A 2009 study found that cats can conceal a cry within their purr that triggers a nurturing instinct in their owners, similar to the cries of a human baby. The study observed that when purring to solicit food, the noise cats made was “more urgent and less pleasant”, suggesting they can manipulate their purrs to communicate different things.

2009年的一项研究发现，猫可以在呼噜声中隐藏一种哭喊声，类似于人类婴儿的哭声，从而激发主人的养育本能。该研究观察到，当猫发出呼噜声以求食物时，声音“更紧迫，不愉快”，这表明它们可以控制自己的呼噜声传达不同的信息。

Cats often purr while under duress, such as during a visit to the veterinarian or when recovering from injury.

猫经常在受到胁迫时发出呼噜声，例如在看兽医或受伤恢复时。

“Soft kitty, warm kitty, little ball of fur! Happy kitty, sleepy kitty, purr purr purr!”

猫咪的purr purr声真的很治愈呢！

Cats purr during both inhalation and exhalation with a consistent pattern and frequency between 25 and 150 Hertz. Various investigators have shown that sound frequencies in this range can improve bone density and promote healing.

而呼噜声修复组织（tissue regeneration）的功能除了帮助猫咪自身疗伤，让其拥有“九条命”，对于人类也大有裨益。

In fact, purr-like vibration devices have been patented for potential use in therapy, and some researchers have proposed strapping vibrating plates to astronauts' feet during long space flights to retain bone density.

事实上，类似呼噜声的振动装置已获得专利，可用于一些治疗。一些研究人员建议在长途太空飞行中将振动板绑在宇航员的脚上以保持其骨密度。