Fricative are often a source of confusion for English learners.

摩擦让很多英语习者感到困惑。

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，可在听诊时闻及心包摩擦。

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

这些都是摩擦，声慢慢地出你会听到摩擦声。

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

最后是清擦或“安静”，出现在诸如 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，要出你已经知道 th ，需要舌头在外面，空气必须通过舌头和牙齿之间，才能出摩擦。

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.

通常表现出心包摩擦，以及ST段抬高和PR段压低等心电图改变，继之呈现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.

在之前一个视频里，我说破擦有点像加法 —— 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，所以声带是振动，产生出这种擦，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.

在之前一个视频里，我们探索了美式英语中两个破擦，或者叫复杂辅。

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

破擦由一个爆破和后面擦组成。

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

另一个思考方法是爆破加上擦等于破擦。

In today's program, we will explore fricatives.

在今天节目里，我们要探索摩擦。

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

英国齿槽、西班牙颤、法国小舌擦？

Next are the fricatives, where two parts touch.

接下来是摩擦，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，可以在前面再加一个齿擦。

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，这是因为我们试图出那个浊齿擦 θ（theta）。在英式英语中，θ 该怎么呢？

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

所以在美式英语中， 组合d-g“dg” 会变成一个塞擦， 在单词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：过程中，两个器接近，而声道变窄程度又不足以产生振荡气流，因此器之间缝隙比擦大而不致产生擦或振荡 (摩擦)。英语中这类有w， I， j。由于 [w] 和 [j] 常常被看作是元，所以这类和元有相似之处。

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

规则如下：浊摩擦出现在清之前时， 将转换为相应清。