From: Brian M. Scott
> Let us take a concrete example. If a certain segment of aNo, they don't.
> population substitutes a fricative (/f/) for an aspirated
> stop (/pH/), we can make one of two basic assumptions:
> that segment finds it difficult (or impossible) to
> replicate /pH/; or that segment does not properly hear
> /pH/, and cannot distinguish it from /f/. Both scenarios
> imply physical causes.