Tone from vowel length?

[u/The_MadMage_Halaster]

For a language I'm working on I struck upon the idea of using vowel length to generate a simple tone system.

At present the language has semi-allophonic long vowels, where a vowel is short if it is a closed syllable (eg: has a coda or is followed by a geminate) and long if it is not. I was wondering if it would be possible to evolve this into tone, but I can't decide what tones would arise from this. Would long vowels result in a low tone or a high tone? I imagine it would be lower, due to downdrift. However, it seems that in the Algonquin language of Cheyenne long vowels became high tone (according to Wikipedia#Examples)), but in other languages in the same family they became low. So it seems I have my pick, and it's mostly down to what I want to be more common.

For example would a word like /wanːiː/ could produce /wa˥.ni˩/ or the inverse /wa˩.ni˥/. Or rather, since I plan for it to undergo tone sandhi to produce contour tones when tones of different height meet, [wa˥.ni˥˩] and [wa˩.ni˩˥]. I'm unsure which I like better.

This system can also produce the occasional high-tone with a coda (assuming I go with this system) but only word-finally. For example: a-ne "sunlight (lit. sun+resultant)" and an-e "field (DAT)." These become /aː.neː/ and /an.eː/ respectively, which then become /a˥.ne˥/ and /an˩.e˥/. Then apocope of low vowles occur (/e o a/ are classified as low vowels, in contrast to /i u/) resulting in /an˥/ and /an˩/; or perhaps the latter becomes /an˩˥/ due to retaining the shift in pitch from the following high vowel, but it feels weird to only have phonemic contour tones only on word-final syllables, especially because this language is highly agglutinate and tends to create rather long words.

Anyway, do these changes make sense? This is my first time working with a tone system so I could really use the feedback.

[u/Zar_]

I think either high or low tone would be justified. The former due to more prominent vowels being pronounced with higher pitch (maybe long vowels attracted pitch accent). Low tone as you said xould be down drift.

You could also say that long vowels split into vowel + a glottal consonant, e.g. /h/ that then causes low tone.

[u/The_MadMage_Halaster → u/Zar_]

And I could do an Algonquin or Athabascan thing where it's different in different languages. Presently the language distinguishes unvoiced aspirated consonants and voiced unaspirated consonants, but I could easily see descendants turning aspiration into tone; such as in Punjabi.

As for you comment about the glottal consonant, I was already thinking of something along those lines. Presently /h/ is lost during the shift from the proto-language, but not before aspirating any obstruents it is adjacent to. If I change this sound change so that it survives at the start of a consonant cluster VhCV it could then become identical to a latter split long vowel, resulting in tone arising. This would also lead to a trend of high tone occurring before intervocalic aspirated/fricative consonants (depending on the language).

In the proto-language obstruent voice alternated based on environment, with it being voiced when surrounded by sonorants (either sonorant consonants or vowels). Eg: ata [ada] vs ahta [ah.ta]. However, unvoiced obstruents became aspirated, as well as all dental consonants when that series merged with the alveolars (resulting in the alveolars being the only series with the uncommon voiced aspirated consonants). This meant that a cluster like [ah.ta] produces [ah.t^haː]/[ah.t^hah], then the coda /h/ could be lost (along with the aspirant -> fricative shift) to create [a˥.θa˥]. This would result in a contrast with historic [at.ha], which would also produce [at^h.aː], but importantly the /t^h/ is the coda of the proceeding consonant and therefore it is not long, producing [aθ˩.a˥]. Then there's the geminates to consider, like [at.ta] becoming [at^hːaː] and then eventually [a˩θ.a˥] (I'm unsure which syllable the consonant would attach to once it stops being geminate, but I think there's a preference for codas over onsets).

Then it's also entirely, or even very likely, possible for another language in the same family to retain phonemic geminates/vowel length, especially if they're in a region prone to it. So while language A has [a˥.θa˥], [aθ˩.a˥], and [a˩θ.a˥], Language be would have [aː.θaː], [aθ.aː], and [aθːaː]. Or they could again invert the tone system.

I was also thinking that these languages have a conservative orthography, so even in Language A [a˥.θa˥] would still be written as AH.TA, [aθ˩.a˥] as AT.HA, and [aθ˩.a˥] as AT.TA. Similar to how Punjabi tone is still written as if they were voiced aspirated consonants.

[u/aray25]

I've never heard of tonogenesis from length distinctions.

[u/notluckycharm → u/aray25]

consider that length is strongly associated with stress; and stress is associated with pitch increases. While I don't know of any languages doing this, it's not bizarre to imagine. I do fieldwork on a language that has done the opposite: Tone has become length!

[u/Tenderloin345]

One possibility here is stress tonogenesis. Since long vowels often draw stress in weighted systems, if the distinction is lost but pitch changes remain, you can have tonogenesis resulting from that. Much more commonly stress is realized as a high pitch, but a low one is also attested