Kevin

Yes pops and clicks are a significant part of removal, but digital audio restoration usually makes a distiction between these (short bursts - pops, thumps and the crackles of old recordings) and other broadband noise (hiss). See for example Digital Audio Restoration by Godsill and Rayner (Springer 1998), or any of the many papers by these authors (many are available online). (Some of the more recent models attempt to model and fix all types of degradation at the same time). There are also models to attempt to fix wow/flutter type distorion too.

Goldwave itself has a pop/click removal function (Effects/Filter/Pop/Click), but I haven't tried it.

Steve -

Personally with a lot of discs to clean, I'd invest the £40 on Clean. Or there are other shareware packages available on the net that do a decent job with minimal intervention. It's some time since I had a look at these but I seem to recall that DePopper was very good - you can download a copy of that and try it. (Sadly Steinberg don't seen to have a trial version of Clean. If you want to see the effect you could e-mail me a section in MP3, for space saving and accept the loss from coding, and I'll run a default convert with clean and send it back to you - MCPearce0ATaolDOTcom with suitable substitutions - that's a zero after my name). It's also possible to invest a lot more money in profession restoration programs.

Mick