Re: /s/ -> /h/ [was: Re: Betreft: Re: k(w)->p]

Rob Nierse wrote:

>Why is it that s becomes h and never the other way round? (I've never seen it)
>Is it because the tongue needs to move more?
/s/ > /h/ involves the loss of a feature - or, in physical terms, the
elimination of an articulatory gesture.  As Dirk said, the only
articulatory difference between /s/ and /h/ is that /s/ has
alveolar constriction while /h/ has no oral constriction.  So changing
/s/ to /h/ merely involves removing the oral constriction.

/h/ > /s/ would involve the addition of a feature.  For some reason,
sound changes that involve the addition of a feature are much less
common than sound changes involving the loss of a feature.  Why this
is, I'm not sure.  It may be because of some 'least effort' principle
(speakers prefer to make as few articulatory gestures as they can
reasonably get away with), or perhaps there's some sort of acoustic
constraint against adding features.  I dunno.

Matt.