kana - Desu pronounced dess: what about other words?

On a CD that came with my text book I hear that desu is pronounced dess. Are there many other words in Japanese, where done of the sound from the kana spelling actually falls off, like in this example, at the end our at any other place?

If I pronounce desu instead of dess, will it sound wrong to native Japanese speakers?

Is there some rule to what vowels our other sounds (mora?) from the kanji to omit?

Thanks.

Answer

This is not a direct answer to your question but let me explain about difference between voicing/devoicing vowels and prolonging vowels.

There are several ways to pronounce です or the likes.

1. des (1 syllable non-moraic 3 morae, /de/ is longer than /s/, sounds chopped foreign)


2. des: (1 syllables 2 morae, /de/ and /s:/ are even, sounds eastern-dialect-ish)



3. desu (2 syllables 2 morae, /de/ and /su/ are even, sounds western-dialect-ish)


4. desu: (2 syllable 3 morae, /su:/ is longer than /de/, sounds feminine)

Japanese ears perceive no.1 as でぇす, no.2 and 3 as the same thing and normal pronunciation of です while no.4 as ですぅ, which is different from the rest and perhaps feminine.

However, English speakers perceive no.1 and no.2 as the same word "des" while no.3 and 4 as another same word "desu". If they fail to differentiate no.3 and 4, they may mix features unique to each of them.