It is a matter of taste, but some people want a small amount of buzz in their tabla. This is called jawari - similar to the jawari buzz of a sitar or tanpura. A loud buzz is annoying and can signify that the head is on its way out. The buzz is often caused by a loose section of the gob (black spot). If you hold the drum up to the light and can see a small section that seems to be loose and vibrating on its own, you can try putting a small dab of crazy glue or nail polish right on that spot. If that is the culprit this will kill the buzz. Do not put glue or polish over the entire gob or you will kill the resonance of the entire drum.