The source of the noise was a new groundwater well that had been drilled, and a pump and variable frequency drive (VFO) motor installed on the district’s property in Claremont. Shortly after the new well went online in August 2014, it became apparent that the motor was producing a high frequency noise during operation.
The installation of Acoustiblok’s All Weather Sound Weather Panels (AWSP’s) significantly reduced the noise for neighboring residents and provided a more permanent and attractive solution than the temporary barriers that had been erected to deal with the issue, the company says.
A sound meter was used to measure the noise levels inside the enclosure and outside once the panels were placed in position. The sound meter readings inside the enclosure close to the pump were 89dB. The reading outside the enclosure (behind the All Weather Sound Panels) was 65dB. This indicates a noise reduction of 24 decibels. In a 10-decibel decrease in sound level, perceived loudness is cut in half to the human ear.
Acoustiblok’s All Weather Sound Panels are not only sound blocking, but sound absorbing. This means they absorb reflective noises and also stop sound from penetrating through the panels. The panels have a high sound transmission class (STC) of 29, as the panels contain large amounts of Acoustiblok’s viscoelastic polymer material. This uses the isothermal adiabatic principle; as sound waves cause the Acoustiblok material to flex, internal friction occurs and the acoustical energy is dissipated into a very small trace amount of heat.
In addition to being effective on high frequency noise, AWSP’s are also effective on low frequencies; the most difficult sound blocking problems are the low frequencies (30 to 100 HZ), the company says. The annoying bass in music is predominately 40 to 80 HZ. Conventional sound barriers do dramatically less sound blocking below 100 HZ, however, because of the Acoustiblok barrier material built into each of the All Weather Sound Panels they increase in sound blocking from 100 HZ down.
The company says the panels are engineered specifically to withstand the most rigorous outdoor and industrial environments; water, moisture, humidity, salt air/water, dirt, dust, constant ultraviolet light, chlorine air, grease, or corrosion. Because they are encased by all-welded aluminum they also prohibit vermin problems.