在美式英語中音標［z］和音標［s］還有沒有區別？

01-02

謝邀。

請莫就以一常用且很難引起誤解的詞, 以自己的耳朵所聽到的外語的口音現象, 來猶豫而有此問。

[自己的耳朵是連接到自己原本語言語感/語言意識。不同語言有不同語感/意識, 這包括語音]

當然有分, [s]跟[z], 是清濁對立的兩個音, 是在英語裡面(請莫在所謂美英式糾結),

有分詞音辨詞義的作用的兩個音。

需要將普通話裡面所沒有的這個濁輔音/有聲輔音[z], 給學習練習起來, 包括練習它

跟其它語音的組合, 並且讓您的發音器官適應, 用以在學講英語時, 來跟帶[s]的音做分別。

這題目萬或有一是因此意而生... 那麼, 請莫心存僥倖, 這是一個需要會發的音。

有區別。

但是題主對這個兩音的聽感也不是沒有道理。

首先搬書(Ladefoged Johnson, 2011, pp. 65-66)

Stops and fricatives are the only English consonants that can be either voiced or voiceless. Consequently, we can revise our statement that vowels are shorter before voiceless stops than before voiced stops. Instead, we can say that vowels are shorter before all voiceless consonants than before all voiced consonants. In this way, we can capture a linguistically significant generalization that would have been missed if our statements about English had included two separate statements, one dealing with stops and the other dealing with fricatives.
We also saw that a voiceless stop at the end of a syllable (as in hit) is longer than the corresponding voiced stop (as in hid). Similarly, the voiceless fricatives are longer than their voiced counterparts in each of the pairs safe, save [ se?f, se?v ], lace, laze [ le?s, le?z ], and all the other pairs of words we have been discussing in this section. Again, because fricatives behave like stops, a linguistically significant generalization would have been missed if we had regarded each class of consonants completely separately.
Fricatives are also like stops in another way. Consider the degree of voicing that occurs in the fricative at the end of the word ooze, pronounced by itself. In most pronunciations, the voicing that occurs during the final [ z ] does not last throughout the articulation but changes in the last part to a voiceless sound like [ s ]. In general, voiced fricatives at the end of a word, as in prove, smooth, choose, rouge [ pruv, smue, t?uz, ru? ], are voiced throughout their articulation only when they are followed by another voiced sound. In a phrase such as prove it, the [ v ] is fully voiced because it is followed by a vowel. But in prove two times two is four or try to improve, where the [ v ] is followed by a voiceless sound [ t ] or by a pause at the end of the phrase, it is not fully voiced.

這裡面需要注意的有幾點：

1. 母音在濁輔音前比在清輔音前長

2. 位於結尾的[ z ]，或清輔音之前的[ z ]，濁聲(voicing)，即聲帶振動並不貫穿始終。前濁，後清。可以理解為發成了[zs]。

3. [ z ]前後都是母音時，[ z ]的全程都是濁的

我想第二點應該是題主產生這種感覺的關鍵。這個特點應該是不分美音還是英音的。而第一點可以作為題主在聽辯時區分清濁輔音的依據。第一點這種現象在其他語言中也很常見，如法語。

另外，像used to這種用法，表示以前常常或者是習慣，是直接讀為[justu]的。（依據是Longman Pronunciation Dictionary，MDict的詞庫）

Ladefoged, P., Johnson, K. (2011). A Course in Phonetics (sixth ed.). Boston: Wadsworth, Cengage Learning.

清濁輔音，區別蠻大的.簡單說來，遇到單詞尾是不響亮的清輔音字母時（如p,t,k,f）就發[s]；遇到單詞尾是響亮的濁輔音字母（如b,d,m,n,r）或母音字母（如a,e,o,u）時就發[z]，這樣做的目的就是為了順口。清輔音發音時僅氣流從嘴裡出來，聲帶不振動，發出的聲音較弱，因此英語里認為清輔音是一種不響亮音，而濁輔音和母音發音時聲帶要振動，發出的聲音大，因此英語里認為濁輔音和母音是響亮音。為了追求發音的順口和協調，英語人民普遍有一個發音傾向，並且大家都在自覺地執行，就是讓清輔音和清輔音連在一起（如[ps],[ts],[ks],[fs]），讓響亮音和響亮音連在一起（如[bz], [dz],[mz], [nz], [rz], [az]），他們認為這樣發音很順口協調。

有區別，一個是發s絲，一個是發磁（電磁）

比如說please的最後的音是［z］但聽起來很像音標［s］。是現在的人已經把［z］讀為［s］了，還是說它們還有區別？