Comment by geocar

I know Japanese does not have a th sound, and I don't think chinese or most other asian languages have it, but am less sure about that. Unfortunately I lack the data needed to substantiate my claim.

    with
    lang_sounds as (
    select
        lang,
        unnest(string_to_array(ipa, null) ) as sound
    from world_dictionary
    ),
    totals as (
    select
        lang,
        count(sound) as sound_count
    from lang_sounds
    group by lang
    )

    select
        lang,
        totals.sound,
        count(sound) / totals.sound_count
    from
        lang_sounds join
        totals on
        lang_sounds.lang = totals.lang
    where sound = 'θ' or sound = 'ð' or sound = 'θ̠' or sound = 'z'
    group by lang, sound
    order by count(sound) / totals.sound_count

This is just a feature of Castilian Spanish: https://en.wikipedia.org/wiki/Phonological_history_of_Spanis... \th\ only occurs naturally in like 5% of the thousands of human languages that have ever existed. Just because those languages are some of the most widely-spoken ones worldwide does not make the sound a commonly-occurring one in a meaningful phonological sense.

It’s true. English and the main Spain version of Spanish are two of the few languages in the world which have the sound. Even most Latin American versions of Spanish (maybe all?) do not have it.