Pronunciation of す in です and the end of ます verbs


I've always been curious about the pronunciation of the す in です and at the end
of 〜ます verbs. Most commonly the "u" sound is inaudible, but sometimes by some
people it's more pronounced, and some people really **go** for it.

Does it vary by age group, audience, gender, region etc in a way that I
haven't picked up on? Can anyone offer any particular guidance for people
speaking Japanese as a foreign language?




This is the result of a well known [devoicing rule in
Japanese](http://en.wikipedia.org/wiki/Japanese_phonology#Devoicing).
Devoicing means that there is no vibration of the vocal folds. For example,
the difference between [s] and [z] is only that [z] is voiced. The IPA
diacritic for devoiced phones is a circle at the bottom of the glyph e.g.
[z̥]=[s]. Although there is still much dialectal,
[idiolectal](http://en.wikipedia.org/wiki/Idiolect) (the way a particular
individual uses words), and lexical (the way a particular word is used by
individuals) variation in devoicing vowels, and in fact, what is called
Japanese vowel devoicing does not in all cases result in merely a devoiced
vowel. Taken from [The Sounds of Japanese (Vance,
2008)](http://www.cambridge.org/gb/knowledge/isbn/item1157656/?site_locale=en_GB):

> The so-called devoiced vowel is actually missing entirely in many cases,
> although traces of it remain as coarticulations in the immediately preceding
> consonant. Some researchers refer to the affected vowel as reduced, and this
> term is more accurate as it covers a wider range of possibilities.

A [coarticulation](http://en.wikipedia.org/wiki/Coarticulation) in a preceding
consonant means that, for a consonant vowel sequence the consonant has been
pronounced (articulated) slightly differently in anticipation of the upcoming
vowel, so different vowels might result in slightly different articulations of
that consonant. Coarticulation is one acoustic feature that complicates speech
recognition/synthesis.

The traditional and most simple description of vowel devoicing, taken from [An
Introduction to Japanese Linguistics (Tsujimura,
2006)](http://ca.wiley.com/WileyCDA/WileyTitle/productCd-1405110651.html),
gives two conditions for devoicing which Vance calls a good first
approximation:

  1. The high vowels /i/ and /u/ are voiceless when they are at the end of the word and are preceded by a voiceless consonant
  2. The high vowels /i/ and /u/ are voiceless between voiceless consonants.

The う in です# and ます# (# represents end of utterance) satisfy the first
condition and so undergo devoicing:

  * desɯ# → desɯ̥# since /s/ is a voiceless consonant
  * masɯ# → masɯ̥# since /s/ is a voiceless consonant

If, for example, we have ですか, the う is still devoiced because /ɯ/ is found
between /s/ and /k/ (/desɯka/) which are both voiceless consonants and so the
2nd condition is applicable. Devoicing a vowel can be tricky if you
deliberately try it in isolation, but to do so just don't let your vocal folds
vibrate.

However Vance offers the following relevant observation:

> Devoicing between a voiceless consonant and a pause is much less consistent
> than devoicing between two voiceless consonants.

There is one immediate complication (among several) to devoicing high vowels;
what happens when a vowel is both devoiced and [pitch-
accented](http://en.wikipedia.org/wiki/Japanese_pitch_accent), as in the /i/
of 四季 /ɕika/? The contradiction is that you cannot have a high pitch on a
phone that isn't voiced (vocal fold vibration, or
[phonation](http://en.wikipedia.org/wiki/Phonation), is what generates that
part of the signal that is perceived as pitch). Usually textbooks (or at least
the two that I know of) in a first course of Japanese linguistics will not
address this contradiction. This paper [Against Marking Accent Locations in
Japanese Textbooks (Hasegawa,
1995)](http://socrates.berkeley.edu/~hasegawa/Accent/accent.html) argues
against this pedagogical simplification:

> The fact that native listeners do hear an accent on a devoiced syllable
> indicates that associating an accent invariably with a high pitch cannot be
> an accurate description of the language. This paper discusses how Japanese
> accent is actually realized and argues that marking accent locations in
> textbooks without a detailed explanation about accent is merely an extra
> complication that introductory textbooks should avoid.

Devoicing becomes rather complicated when intonation and other exceptional
cases are considered, but just looking at the sheer number of papers on the
topic it seems to be a well studied and documented feature of Japanese
phonology.




This is the result of a well known [devoicing rule in
Japanese](http://en.wikipedia.org/wiki/Japanese_phonology#Devoicing).
Devoicing means that there is no vibration of the vocal folds. For example,
the difference between [s] and [z] is only that [z] is voiced. The IPA
diacritic for devoiced phones is a circle at the bottom of the glyph e.g.
[z̥]=[s]. Although there is still much dialectal,
[idiolectal](http://en.wikipedia.org/wiki/Idiolect) (the way a particular
individual uses words), and lexical (the way a particular word is used by
individuals) variation in devoicing vowels, and in fact, what is called
Japanese vowel devoicing does not in all cases result in merely a devoiced
vowel. Taken from [The Sounds of Japanese (Vance,
2008)](http://www.cambridge.org/gb/knowledge/isbn/item1157656/?site_locale=en_GB):

> The so-called devoiced vowel is actually missing entirely in many cases,
> although traces of it remain as coarticulations in the immediately preceding
> consonant. Some researchers refer to the affected vowel as reduced, and this
> term is more accurate as it covers a wider range of possibilities.

A [coarticulation](http://en.wikipedia.org/wiki/Coarticulation) in a preceding
consonant means that, for a consonant vowel sequence the consonant has been
pronounced (articulated) slightly differently in anticipation of the upcoming
vowel, so different vowels might result in slightly different articulations of
that consonant. Coarticulation is one acoustic feature that complicates speech
recognition/synthesis.

The traditional and most simple description of vowel devoicing, taken from [An
Introduction to Japanese Linguistics (Tsujimura,
2006)](http://ca.wiley.com/WileyCDA/WileyTitle/productCd-1405110651.html),
gives two conditions for devoicing which Vance calls a good first
approximation:

  1. The high vowels /i/ and /u/ are voiceless when they are at the end of the word and are preceded by a voiceless consonant
  2. The high vowels /i/ and /u/ are voiceless between voiceless consonants.

The う in です# and ます# (# represents end of utterance) satisfy the first
condition and so undergo devoicing:

  * desɯ# → desɯ̥# since /s/ is a voiceless consonant
  * masɯ# → masɯ̥# since /s/ is a voiceless consonant

If, for example, we have ですか, the う is still devoiced because /ɯ/ is found
between /s/ and /k/ (/desɯka/) which are both voiceless consonants and so the
2nd condition is applicable. Devoicing a vowel can be tricky if you
deliberately try it in isolation, but to do so just don't let your vocal folds
vibrate.

However Vance offers the following relevant observation:

> Devoicing between a voiceless consonant and a pause is much less consistent
> than devoicing between two voiceless consonants.

There is one immediate complication (among several) to devoicing high vowels;
what happens when a vowel is both devoiced and [pitch-
accented](http://en.wikipedia.org/wiki/Japanese_pitch_accent), as in the /i/
of 四季 /ɕika/? The contradiction is that you cannot have a high pitch on a
phone that isn't voiced (vocal fold vibration, or
[phonation](http://en.wikipedia.org/wiki/Phonation), is what generates that
part of the signal that is perceived as pitch). Usually textbooks (or at least
the two that I know of) in a first course of Japanese linguistics will not
address this contradiction. This paper [Against Marking Accent Locations in
Japanese Textbooks (Hasegawa,
1995)](http://socrates.berkeley.edu/~hasegawa/Accent/accent.html) argues
against this pedagogical simplification:

> The fact that native listeners do hear an accent on a devoiced syllable
> indicates that associating an accent invariably with a high pitch cannot be
> an accurate description of the language. This paper discusses how Japanese
> accent is actually realized and argues that marking accent locations in
> textbooks without a detailed explanation about accent is merely an extra
> complication that introductory textbooks should avoid.

Devoicing becomes rather complicated when intonation and other exceptional
cases are considered, but just looking at the sheer number of papers on the
topic it seems to be a well studied and documented feature of Japanese
phonology.

