It depends on the value you choose.  In the frequency domain, a cap looks like
1/(2*PI*f*C) which means for higher frequencies, the impedance is higher.
So, choosing a smaller value cap may provide a reasonably small impedance
at lower audio frequencies and a high enough attenuation at radio frequencies.

Plug .01uF into the equation. Use audio frequencies for f and then try
radio frequencies for f.  If this is a resonable value, use that, otherwise
try other values of C.

                                        - Dennis

At 03:10 PM 1/19/99 +0530, you wrote:
>Hmm, I'm no smartie, but wouldn't a capacitor eliminate your voice as well,
>as it's an AC type thing? So you'd just get a DC current, or silence. Maybe
>one of the experts can comment on it...
>