Re: /p/ versus devoiced b?

Imperative wrote:
>Why is it that /p/ and devoiced /b/ sound slightly different? I recall
>reading somewhere that it has something to do with fortis and lenis
>voiceless (or I could be mistaken?)
We should ask Yoon Ha.  Korean has a three way contrast between voiceless
stops: aspirated, unaspirated, and fortis.  Is the devoiced /b/ the fortis
stop?

The three Korean grad students in my phonetics class told us that fortis
stops were produced by stiffening the vocalis folds so that there was no
vibration in the larynx.  This made things as clear as mud to me.  There
were slightly audible differences between individual unaspirated and fortis
pairs which they produced for us, but I could never generalise the
difference and recognise what made them different.

E-Ching