On Fri, 27 Jan 2012 12:07:32 -0800, Paul Drahn
wrote:


But metal heating/ac ducts make "dripping" noises as they warm and cool.
The metal in the joints move against each other and where the ducts are
touching wood.

Paul

A regular here posted a link (thanks) the other day to InspectAPedia®.

For giggles I was looking into building sounds (expansion /
contraction). Interesting stuff.

Noise:

_How to Diagnose, & Repair Noise Problems in Building Interiors_


http://www.inspectapedia.com/interiors/House_Noise_Diagnosis.htm

"...Health, neurological, and psychological sources of annoying noise
or sound complaints ..."