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。

词汇：sound 声音

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.

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.

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.

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.

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.

词汇表

meow 猫叫声，喵喵叫
hiss 嘶嘶声
purr （猫发出的）咕噜声
pulsing 脉冲的
inhale 吸气
exhale 呼气，吐出气
onomatopoeia 象声词，拟声词
frequency （声波的）频率
hertz 赫兹
laryngeal 喉部的
vibrate 震动，颤抖
vocal cords 声带
endorphin 内啡肽，安多芬
vibration 持续震动
ripple （声音）传播起伏
roar 吼叫

测验与练习

1.  阅读课文并回答问题。

1. True or false: cats purr when they breathe in and out.

2. Why does Eddie Izzard compare purring to drilling?

3. What is the word ‘buzz’ an example of?

4. Why might the brain release endorphins?

5. Do all cats purr?

2. 选择意思恰当的单词或词组来完成下列句子。

1. If one _______ too deeply, they may cough.

exhale                          exhalation                 exhales                    exhaling

2. Listen to that tiger _______. It’s terrifying.

roared                           roars                         roaring                     was roaring

3. The seat _______ to massage your back.

vibrating                        vibrate                      vibration                   vibrates

4. Be careful when _______ – try not to breathe too deeply.

inhaling                         inhales                      inhale                      inhalation     

5. The sounds _______ through the air.

ripples                           rippling                      rips                          rippled

答案

1.  阅读课文并回答问题。  

1. True or false: cats purr when they breathe in and out.
True. Cats purr when they inhale and exhale.

2. Why does Eddie Izzard compare purring to drilling?
It was a joke. Drilling is a similar sound – they both pulse.

3. What is the word ‘buzz’ an example of?
‘Buzz’ is an example of onomatopoeia – a word pronounced like it sounds.

4. Why might the brain release endorphins?
As a reaction to pleasure or pain.

5. Do all cats purr?
No. Big cats like lions don’t usually purr.

2 .  选择意思恰当的单词或词组来完成下列句子。

1. If one exhales too deeply, they may cough.

2. Listen to that tiger roaring. It’s terrifying.

3. The seat vibrates to massage your back.

4. Be careful when inhaling – try not to breathe too deeply.

5. The sounds rippled through the air.