The drain functions properly but when you turn the water on , unless using a higher pressure from the faucet - it is very loud and trickles and the sounds echo throughout the pipes under the sink itself. I did a search on this, and most people say it's air in the pipes - but it's not an issue of that or pipe placement. Any suggestions - I didn't really word the problem too well, it's hard to describe... If I use the faucet on low pressure - water seems to echo throughout the assembly, if on higher pressure, it's not that noticeable.

It's not air in the pipe. Sounds like a loose washer. Does this occur on hot, cold or both. Loose washer could be in faucet or stop valve. What kind of sound? What kind of faucet?

It's not really in the faucet - it's like echoing in the pipe below the actual drain - like the pipe is too big? Nothing is loose.
Thanks for the quick reply

Hawk,
Don't be so quick to discard Harolds advice. Noise in plumbing = vibration.
You either have something loose in the faucet itself or a loose washer in the angle stop. Now would be a mighty fine time to tell us what type of faucet you have, one handle or two knobs and its brand name? Take your hand and tell us exactly where the vibration feels the strongest. Is some cases water pipes will pick upm the sound and carry it throughout the house. This is called "sympathetic vibration". Let us know what you find. Good luck, Tom

I would love it if it was in the faucet, it is a moen, one handle, only a year old.
Seriously - it's an echo of water trickling through the pipes, literally high pitched tinkling, and echo as the water passes from sink to drain to pipe

If you pour water down the drain from another source do you get the sound.

No - just down the other side of the sink into the same drain

Sorry, I don't understand you response. Is this a double sink. Are you saying that you don't get the noise if you pour water down the drain with out running the faucet? Or are you saying that you don't get the noise if you run water down the other side of a double sink.

The noise occurs with water ON or with the water OFF and just taking a pither and pouring water down either side of the dual sink is just the same - just loud, hearing the water echoing through the drain, and the pipe, just about to the trap - seems to have nothing to do with the water source

Hey, massplumber helped me out on that one. The water is probably hitting the trap square. Can make an awful sound with a 2 drain sink and a PVC drain.

Fix: Intentionally missalign the drain