Of all the languages for which there is sufficient data, including extinct languages, which vocalic speech sound, or phone, as represented by the IPA, has been used most?

  • 1
    By whom? As allophone or phoneme? In which transcription system? With what phonological rules? Etc. The question is not answerable, alas.
    – jlawler
    Commented Oct 1, 2012 at 1:05
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    Vowels are a continuum, so that's probably hard to answer. One way to make the question more answerable might be: Grouping vowels with respect to close/mid/open, front/mid/back and unrounded/rounded, which is the group populated by the most languages. I guess it would also depend on how exactly you distinguish a language from a dialect...
    – dainichi
    Commented Oct 1, 2012 at 2:08
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    Except that "languages" do not "use" IPA symbols. Linguists use IPA symbols, and they use them for many different purposes, phonemic, phonetic, orthographically, educationally, etc. The question is still unanswerable, without further qualification.
    – jlawler
    Commented Oct 1, 2012 at 16:48
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    Given that schwa-centering of unstressed vowels is a common phenomenon it may be the most 'common' in production, but then in those it is only a an allophone, not the underlying form.
    – LaurenG
    Commented Oct 1, 2012 at 20:15
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    the comments above are good to keep in mind. the answer is probably /a/. google "Simple UPSID Interface" to get some quantitative data.
    – user483
    Commented Oct 1, 2012 at 21:20

3 Answers 3


In spoken language it is very likely the schwa [ə]. The schwa is frequent in speech due to a common form of vowel reduction, centralization. This is especially present in rapid speech where vowels may not be perfectly articulated all the time. Also, many languages that are written abjad-wise have the schwa as their most frequent vowel phoneme.


The answer primarily hinges on the meaning of the construction "has been used by more languages, with more frequency than any other", especially whether "with more frequency than any other" adds anything to the question, i.e. whether it means "and occurs with greater token frequency than any other". Since I cannot think of any reason to interpret the clause in that way, I assume that is just another way of asking which vowel is found in more languages. The top contenders are [i] and [a], which in UPSID are a dead heat (language count i=393, a=392). Schwa on the other hand only appears in 134 languages. I would say that it is currently unknown which of a vs. i is found in more languages.

  • Thanks! Is the UPSID data analysis linkable?
    – Lucas
    Commented May 19, 2015 at 4:14
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    Sort of. linguistics.ucla.edu/faciliti/sales/upsid.zip has what you need, though figuring out the encoding is not totally trivial. Also look at web.phonetik.uni-frankfurt.de/upsid_segment_freq.html for an online list of segments and frequencies. The main problem will be merging across diacritics, i.e. nasalization, tone, stress blah blah blah aren't relevant to the question to asked, but they are all treated as separate phonemes, so you have to sum up across diacritics.
    – user6726
    Commented May 19, 2015 at 5:14

A or/and E.

Vowels are much more of a continuum than consonants. Within each language different vowels are separated by different contrastivity, like height, backness and roundness. These contrast lines are very much dependent on how many different vowels the language is believed to use phonemically.

One way to describe these vowel sounds, is to write them in plain writing, using the appropriate alphabet. This is not the same as IPA-alphabet, but it is still the most frequent way to describe a vowel sound. It is also a way to actually making continuus vowel sounds to be discrete.

There exists several lists counting letters in languages. This Wikipedia page gives an overview: http://en.m.wikipedia.org/wiki/Letter_frequency

The question is also difficult to answer, because you are mixing frequency of languages and frequency within languages. What counts most, people talking, percentage of usage worldwide, or percentage of usage within each language?

  • This answer doesn't actually answer the question proper: the asker didn't inquire about the frequency of letters but of the frequency of phone(me)s as found in varying languages.
    – Darkgamma
    Commented Dec 7, 2014 at 20:31

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