Noise insulation requires some engineering expertise

Q. My house is a single-story-with-basement row home. The problem is noise. The firewall is cinder block. Two years ago a carpenter put up 2x4s along the shared bedroom wall, insulation batts were added, and plaster board installed. It helped but not nearly enough. I can still hear the sound of a cuckoo clock next door -- not just the cuckoo, but the tick. Any ideas? A Pennsylvania reader

A. Sound-control techniques have advanced considerably in the last decade or two. The present state of the art should be equal to further control of the unwanted sounds in your row house.

Just where can one find such expertise? Some architects and engineers specialize in the design and construction of sound barriers in both new and existing buildings. A few local telephone calls should uncover the names of such experts. See the Yellow Pages under "acoustical consultants," "acoustical contractors," and "acoustical materials."

After checking the reliability of two or three likely professionals, choose the best one, in your judgment, to inspect your particular building. From that inspection should come not only how unwanted sounds pass through the walls of your row house but also how to stop or diminish them.

You were on the right track when a second wall was installed, but likely special care at what might appear as trivia may have been overlooked by the carpenter. For example, noise emits through electrical outlets and switches and even between the bottom and top plates of the stud walls.

Sound insulation is not necessarily the same as thermal insulation. The type and manner of placement of the insulation is critical to sound control.

Sounds may be airborne or travel through the structure in the form of vibrations. Now you can see why it takes an acoustical expert to diagnose the problem and offer a solution?

For pertinent information write to the Institute on Noise Control, 3456 Altona Road, Bethlehem, Pa. 18017 or call (215) 694-0939.

After plans and specifications for sound-control work have been prepared by your consultant, obtain two or three competitive bids from acoustical contractors. Go with the lowest responsible bidder.