Eckel Acoustics

Functional (Unit) Sound Absorbing Panels Reduce Noise Levels In Waste Water Treatment Facility

By Alan Eckel - President, Eckel Industries, Cambridge, Mass.

In October 1996, rooms within the integrated wastewater and sludge treatment facility were evaluated as to their noise problems. Based on these studies, several rooms would need to be treated with Unit Sound Absorbing Panels.

Acoustical treatment to achieve maximum noise reduction was calculated. Functional (unit) Sound Absorbing Panels (Eckoustic Functional Panels - EFP's) were installed on the ceilings and walls of both rooms. Average noise level in the pump room was reduced to 85 dBA and in this blower room to 82 dBA bringing the rooms into OSHA compliance, and reducing reverberation to levels that did not interfere with communication between workers.

Noise and reverberation (echo) are two things that audio engineers want to control. When I thought about this article I wanted to consider these two separate effects in two different situations - the closed broadcast studio where you sit and speak in a silent room and the open-concept studio where an audience, or video as well as audio, affects the sound quality. Noise - that sound which is loud, harsh or unwanted - and reverberation - the reflected noises that echo or bounce back - can be controlled, even to the extent that they can enhance the recorded or broadcast signals.

Hearing Aid Technology Program Using Eckel Audiometric Rooms

Bates Technical College - Tacoma WA under the direction of Allen Webb-MA-CCC-A offers a Hearing Aid Technology course to certify students as qualified Hearing Aid Technicians. Bates Technical College uses a 5 room multiple suite incorporating two single-wall/double wall suites and an observation room accessible from the classroom.

Large volume areas with hard reflective surfaces may be functional, but when you introduce people and their activities the resulting noise is contained by the walls and the resulting condition is call reverberation.

All construction materials have some absorbative qualities, many like concrete, glass and steel are low on the absorption scale. Noise energy is easily reflected off of these materials, within a confined space, to produce an echo, or reverberation effect. If, for example a construction surface such as concrete was perfectly flat, hard and non-yielding, then all the acoustic energy (noise) would be reflected and the Absorption Coefficient would be zero (0.0.)

By Alan Eckel - President, Eckel Industries, Cambridge, Mass.

The basic purpose of a sound room in audiometric testing is to provide the proper acoustical environment so that tests can be conducted without interference from outside noise. A room of this type should afford adequate ventilation and lighting so that the subject will be comfortable while his hearing is being evaluated. Not only does the room supply environmental control but it eliminates distraction from changes on the visual horizon which may invalidate an audiogram as readily as acoustical interference.

Whether it’s a long-term strategy to replace all noise machines or an immediate goal to better maintain machinery already in place, noise control and reduction measures are the best way to protect worker hearing.

In industry, noise is more than an unwanted part of the work environment; it is often a destructive force that takes a toll on both people and materials. In the short term, exposure to high noise levels can have a psychological effect on workers, causing irritability and mental fatigue - which in turn can lower productivity and even contribute to accidents. In the long term, exposure to high noise levels can be even more damaging by causing noise-induced hearing loss - the irreversible loss of the ability to hear.