Toilets noisy.

[Doctor]

Basement toilet started making a noise several years ago. Approximately 10 seconds after a normal flush, there is a 'vibrating' noise. My main floor toilet has just started to make the same noise. Is this a venting issue? How do I fix it?

[pushkins]

Does it happen while the tank is refilling?
If so try either opening or closing just a little the water shut off valve, sometimes these can get a little hum going.