Someone else reported this sound last September, but there wasn't any resolution to that thread: After upgrading to Snow Leopard on my Mac, Firefox makes typewriter or paper crinkling sounds when going to links and sites.

Does it seem to be at all related to whether pages use Flash? Just wondering whether it is some kind of notification sound related to Flash's capabilities of using the webcam and microphone.

Thanks for your reply. I actually saw the other posting as well, and while initially encouraged that someone else had brought up this topic, was disappointed to see its unresolved status.

It does not seem to be a flash issue as the sound still occurs when I disable the flash plugin and I don't get the sound in any other browsers.

In Collusion, can you check the Filters tab and see if sounds are enabled there?

Also a helpful suggestion and clarifying image. I checked the collusion filters tab and the sound was already disabled.

I just noticed that on the NoScript Options > Notifications tab there is an audio feedback option, but the default sound is nothing like a typewriter.

If it still occurs with all extensions disabled, I'm baffled.