Fricative are often a source of confusion for English learners.

摩擦音让很多英语学习者感到困惑。

First, when the thickened layers of the pericardium rub up against each other - it creates a friction rub which can be heard on auscultation.

当增厚两层心包膜互相摩擦，可听诊时闻及心包摩擦音。

These are all fricatives, the sounds are coming out slowly and you hear this friction sound.

这些都是摩擦音，声音慢慢地你会听到摩擦声。

And finally, the vociceless fricative or be quiet sound, shhhhhh, present in words such as shower and push.

最后是清擦音或“安静”音，诸如 shower 和 push 等词中。

So, to make the th sound you already know, I hope that the tongue needs to be outside, and the air has to pass between the tongue and teeth in order to create this friction sound.

所以，要你已经知道 th 音，需要舌头外面，空气必须通过舌头和牙齿之间，才摩擦音。

It usually results in a friction rub, as well as ECG changes like ST elevation and PR depression, followed by T wave flattening and inversion.

通常表心包摩擦音，以及ST段抬高和PR段压低等心电图改变，继之呈T波低平和倒置。

In a previous video, I described affricates as being kind of like addition - one plus one equals two.

之前一个视频里，我说破擦音有点像加法 —— 一加一等于二。

You're releasing air with sound, so the vocal cords are vibrating and creating this friction sound which is the 'V' as of the word 'very', 'vicious' and 'seven'.

是要通过释放口腔里空气带动音，所以声带是振动，产生这种擦音，即‘V’，比如单词‘very’、‘vicious’和‘seven’。

To be clear, fricatives mean there is a partial obstruction in the air stream.

清楚地说，摩擦音指是气流有一部分被阻滞。

In a previous video, we explored the two affricates, or complex consonant sounds, of American English.

之前一个视频里，我们探索了美式英语中两个破擦音，或者叫复杂辅音。

Affricates are made up of a stop sound followed by a fricative sound.

破擦音由一个爆破音和后面擦音组成。

Another way to think of this is stop sound plus fricative sound equals affricate.

另一个思考方法是爆破音加上擦音等于破擦音。

In today's program, we will explore fricatives.

今天节目里，我们要探索摩擦音。

The English alveolar approximant, the Spanish trill, the French uvular fricative?

英国齿槽音、西班牙颤音、法国小舌擦音？

Next are the fricatives, where two parts touch.

接下来是摩擦音，其中两个部位接触。

You can put another sibilant in front of that if you want.

如果你想话，可以前面再加一个齿擦音。

Yeah, that happens because we're trying to make that the that voiced dental fricative, the theta, which how do you pronounce that in UK English theta?

是，这是因为我们试图那个浊齿擦音 θ（theta）。英式英语中，θ 该怎么音呢？

So the combination d-g sound, " dg" is an affricate in American English for judge becomes " j" .

所以美式英语中， 组合音d-g音“dg” 会变成一个塞擦音， 单词judge中变为“j” 。

As [j] and [w] can also be analyzed as vowels, it is an important point to note that this category overlaps with that of vowel.

(4) 通音：音过程中，两个音器接近，而声道变窄程度又不足以产生振荡气流，因此音器之间缝隙比擦音大而不致产生擦音或振荡 (摩擦)。英语中这类音有w， I， j。由于 [w] 和 [j] 常常被看作是元音，所以这类音和元音有相似之处。

The rule reads: a voiced fricative is transformed into the corresponding voiceless sound when it appears before a voiceless sound.

规则如下：浊摩擦音清音之前时， 将转换为相应清音。