Like most of Clement's novels, Noise is an exploration of a very odd world. Much of what's interesting is the world-building. In Noise, we explore a true water world -- a terrestrial planet with an ocean 3000 km deep. The world has odd weather and other strange properties which make it somewhat hostile to human habitation, and much of the novel explores how humans deal with the challenges.
The noise in the title refers to the fact that the environment is so chaotic that no form of long distance communication is practical. Sonic noise prevents speaking or sound messages from being used over any distance; atmospheric conditions restrict visibility to a kilometer or two, and constant storms provide so much radio interference that long range electromagnetic communication is impractical.
On top of this, Clement gives us a moderately interesting story about the people, and presents a bit of an intellectual puzzle for the reader to figure out what the real point of the story is.
The one flaw in the story that really bothered me is that he makes a key plot device out of silicon being effectively non-existent in the ocean and therefore computer technology is almost unavailable to the inhabitants. Every time it came up, I felt the urge to scream, because silicon is not the only -- in fact, not even the best by a long shot -- semiconductor to make computers out of. By the time human technology has advanced as far as the biotech goodies that make this civilization possible, it's a sure thing that they'd be able to make computers out of other things if silicon wasn't convenient (assuming anyone is still making computers out of silicon anywhere, which is less than likely). The rest of the science seems so solid that this really stands out as a gaffe.
Except for the no silicon = no computers thing, I definitely enjoyed this novel. If I could ignore the silicon issue, I think it would be my favorite Hal Clement novel and I'd give it a 9, but that gaffe really got on my nerves, so my rating will be a 7 out of 10.
A sad postscript is that this is probably the last Hal Clement novel, since Harry Stubbs ("Hal Clement"'s real name) passed away recently. We've been losing too many of the old guard SF authors lately.