Sheriff’s Office – Sound Masking

The Pinellas County’s Sheriff’s Office was struggling with a number of noise complaints. Among other things, they were concerned with the sound privacy in interview rooms, to ensure that interviews were conducted in a confidential manner.

So they contacted Commercial Acoustics. After an initial site visit, we prepared a solution that would provide significant speech privacy without the need for a major construction budget. By pairing sound masking speaker systems with additional soundproofing wall membranes, we were able to increase the STC of the walls while also masking background noise.

The combination of the two approaches yielded impressive results: primarily, that officers no longer needed to worry about being overheard while they worked (and were not distracted by other conversations). While the sound masking system was installed, tuned, and implemented in a single day, the soundproofing membrane for the walls required an additional several weeks to complete each of the 10 interview rooms. This is a level of soundproofing that many law enforcement agencies do not require, but which provides superior soundproofing for a wide array of applications.

For many clients, the benefit of sound-masking cannot be over-stressed. The highly-tuned speakers provide an exceptional ability to mask background noise, and thereby reduce the “dynamic range” that so many office employees find extremely distracting. The speakers are hidden from view, concealed behind the ACT. They do not interfere with voice recordings, and actually enhance the speech privacy over phone conversations. Affordably priced, at approximately $1.00-$2.50/square foot, it can make the difference between a noisy workspace and an acoustically-treated office.

Sound Masking for Open Offices

Sound Masking Unit

In open layouts – whether it’s offices, libraries, or museums – noise often becomes a major concern. Without a proper background noise, loud noises are particularly distracting, due to the Dynamic Range that occurs (difference between quietest and loudest moments). Large dynamic ranges make it difficult for employees to concentrate or visitors to enjoy the space.

We apply the ABC (Absorption, Blocking, Cover) approach to many of our consultations, but open spaces often don’t allow for sound-blocking solutions, and additional absorption makes little or no improvement.

Sound masking is the addition of a white noise or pink noise system of light background sound. This particular frequency of sound essentially helps break up the silence and reduce audible distractions of human speech or impulse sounds. When used correctly, sound masking systems allow for greater productivity, increased privacy and comfort and a more enjoyable workplace.

Speech privacy and sound masking go hand-in-hand. Speech privacy is the ability of an unintentional listener to overhear and understand another person’s conversation. This is common in large ‘bullpen’ open office environments or in adjacent offices where walls don’t go to deck and sound has a clear flanking path to transfer in and out. Not only is a lack of speech privacy distracting it can also become a breach of confidentiality in law offices or physician patient rooms.

One recent project Commercial Acoustics treated was a library in Pinellas County, Florida. Readers were often distracted by a “Makers Area” where louder interaction was common. Since the wall didn’t go to deck and deck and it wasn’t possible to add a barrier between the areas, sound masking was the obvious solution. Masking consists of speakers that hang above the area (often concealed by ceiling tiles) that create a constant, homogeneous background noise at a decibel level that the visitors don’t notice but masks unwanted sounds. In this area, we spaced the speakers at 15 ft on center, and implemented a 45 dBA background (lower than most office settings). Within 2 weeks and at about $1 per square foot, the masking system was installed and calibrated, allowing the library to prevent future noise complaints and improve its visitors satisfaction.

Sound Masking Layout