On Tue, 2010-05-11 at 02:00 -0500, Eric Christopherson wrote:

> Thanks for the replies, everyone. Now I'm trying to find an old message that was talking about tones coming from final /?/.

That may have been me! Tonal contrasts from the loss of final consonants
only seem to come from /ʔ/ and /h/, although these may represent earlier
oral stops and continuants. Each can go two ways.

/ʔ/ usually leads to a creaky voice register that becomes a high tone,
but it can also leave a low tone if it was a simple arrest that didn't
colour the vowel. Thus the Athbascan suffix -taʔ gives Chipewyan -tó but
Sarcee -tò. In Asia, the high tone is usual.

Similarly, -h usually leaves a breathy register that becomes a low tone,
as in Vietnamese, but can lead to a high tone (via lengthening?) as in

The voiced/voiceless contrast only seems to affect tone when it's
initial (voiced > low, voiceless > high). Maintaining the contrast at
the end of the word takes some effort — think of how many languages
don't do it — so if a language weakened its final stops, the voicing
contrast would probably go first, and then the resulting voiceless stops
could become /ʔ/.