Flaky mic in TDD built in phone coupler - sources?

[Fred Cisin]

On Sat, 1 Oct 2005 jpero at sympatico.ca wrote:
> This is round 5/16" dia mic with felt screen stuck over the small
> opening.
> Now mic working intermittently and had to tap even bang on it to
> wake up.

What kind of mike is it?
Some types are prone to "carbon granule clumping", and need to get shaken
up and beaten on occasionally.


> Now today, I'm planning to combine my mic search with downtown
> shopping,  will these mic robbed from cheap headphone with mic with
> 1/8" jack work?

What's the impedance?