Re: Directionality of Sound changes

--- In phoNet@yahoogroups.com, Miguel Carrasquer <mcv@w...> wrote:

> Reading past posts, on 08-08-03 Piotr wrote:
> >Likewise, deletion is more common than epenthesis, but both _may_
> >happen, as Richard has pointed out.
>
> Isn't it so that it _must_ happen?
>
> I would think the true "axioms" of sound change are:
>
> 1) there are no "sinks"
> 2) there are no "sources"
>
> Every phoneme /x/ must have at least one out-transition (/x/ -
> /non-x/)
> and at least one in-transition (/non-x/ -> /x/). Otherwise, the

sources

> would have long ceased to be possible phonemes, and sound-change

would have

> stopped altogether as soon as all phonemes had been attracted to

the sinks.

This should then apply to any proper subset of human phones, e.g.
nasals or clicks. Powerful axiom, this. An axiomatic motivation
for rhinoglottophilia and the change of final plosives to nasals!

> Now, since we know that for the null phoneme, sound changes /x/ -
> /0/
> exist, there must also be transitions /0/ -> /x/ (something from

nothing).

What are the phonotactics of null phones? How many can we have
between non-null phones?

> To be sure, epenthesis is not the main mechanism (which I think is

word

> composition, operating at the lexical/semantic level, above the
> phonological level).

Word-initial Germanic *p and German /p/ come to mind as problems
with the logic here. They weren't established by sound changes.

Richard.