随身英语 !u0U5>ccw Gc}0]!nrW9 1Zq Why do cats purr? 猫咪为什么发出咕噜声？ $~hdm$ 
Play audio file /,t|
!)\] 众所周知，猫会发出喵喵声、嘶嘶声和咕噜咕噜声。但有一个问题让人们感到困惑，那就是猫为什么会发出咕噜咕噜的声音。我们通常认为猫咪发出咕噜声是因为它们很
快乐，不过原因可能没有这么简单。
Em9my2oE 词汇：sound 声音 ScHlfk
p We’ve all heard cats
meow and
hiss, but why do they
purr? There are a number of theories out there - from the commonly held belief that they are simply happy, to British comedian Eddie Izzard’s light-hearted suggestion that they are impersonating a drill.
onh?/3l While they do purr when tickled or caressed to show their appreciation for attention, cats also make the noise when not in our company. The purring noise is a consistent
pulsing sound that occurs while they both
inhale and
exhale breath. The word ‘purr’ is a great example of
onomatopoeia and refers to the constant noise which ranges in
frequency between 25 and 150
hertz.
t'Htx1#Zc[ For a long time, scientists debated how cats purred. 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. What triggers this reaction is debated. Some argue that the cat intends to purr, while others say it may be due to
endorphins released by the brain as a reaction to pleasure, or pain.
cUM_ncYOP According to Leslie A. Lyons, an assistant professor at the School of Veterinary Medicine at the University of California, cats often purr while stressed, such as when they head to the vets or are recovering from an injury. So what are the potential benefits of this ‘drilling’ sound? Some scientists believe the
vibrations that
ripple through the cats’ bodies may actually promote muscle development, heal bones and injuries, ease breathing and lessen pain. It could even help to soothe discomfort in a similar way to a child sucking their thumb.
]
zIfC>@R So, the purring of a cat may have more uses than just telling you they’re enjoying attention. It’s also important to remember that not all cats can purr. Some bigger felines, like lions, can’t, and only
roar. So, the next time you hear a roar, it probably isn’t your pussy cat, and you might need to run.
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