Are Your Video Conference Room Acoustics HD-Compatible?

Are Your Video Conference Room Acoustics HD-Compatible?

There are many market factors driving the growth of video conferencing, and manufacturers like Polycom and ClearOne have responded with better technology. These modern video conference systems offer bigger displays, higher resolution video, high definition audio quality, integration with mobile apps, and so on. However, if this advanced technology is installed in a poorly designed conference room, the results can be disappointing. A good conference room design and system installation takes into many factors, including lighting, background color and patterns, camera and video display locations, microphone and loudspeaker type and placement, background noise, and room acoustics. This post will focus on ways that the room design can enhance or reduce the audio quality of the system. A follow-up post will provide more detail on good room design principles to get the best audio quality possible out of any videoconferencing system. The advent of HD audio quality Traditional video and teleconferencing systems relied on telephone connections for communication, which inherently limited the audio quality. For example, landline phones are filtered to a narrow range of frequencies that are most important to speech intelligibility. As a result, voices can still be understood, but they don’t sound as natural as they would if you were in the same room with the person. Compare these two audio files to see if you can hear the difference in quality: unfiltered audio  audio with telephone filter As we move away from landlines to cell phones and VOIP systems, there are other ways that audio quality can be compromised. High quality digital audio requires a lot of data and causes network congestion. Phone systems try to...
Sound Masking for Speech Privacy

Sound Masking for Speech Privacy

Many open office areas employ electronic sound masking systems to create an even distribution of background noise that is just loud enough to help mask distracting noises (particularly from other conversations) without being loud enough to be a nuisance. The system typically consists of special loudspeakers mounted in or above the ceiling and a head-end unit that generates and shapes the noise. Another useful application of sound masking is to improve speech privacy between rooms. Privacy is traditionally assessed simply by using the Sound Transmission Class (STC) of the partition between two rooms. However, this is only part of the picture. Privacy is dictated both by how much sound passes through the partition (STC) and the background noise level in the receiving room. Obviously, it is easier to eavesdrop on a conversation if the receiving room is quiet. There are many situations where privacy is important and the background noise level can be used to our advantage. Speech privacy is important in healthcare where HIPAA requires that “reasonable safeguards” be taken to protect the privacy of patients’ personal healthcare information. The 2014 FGI Guidelines for Hospitals and Outpatient Facilities acknowledges the effect of background noise on privacy in the STC requirements between Exam Rooms. Table 1.2-6 requires STC 50 between Exam Rooms unless there is an electronic masking system, in which case only STC 40 is required. A 10-point difference in the STC rating is significant, and it may be less expensive to build STC 40 walls and install a sound masking system in an exam area than to build STC 50 walls and no masking. Sound masking can...
Beware the Gypsum Association Manual STC Ratings

Beware the Gypsum Association Manual STC Ratings

Do you select Sound Transmission Class ratings from the Gypsum Association Fire Resistance Design Manual? The GA manual contains a lot of good information on fire and sound ratings. The sound ratings, however, must be used carefully. Knowledgeable acoustic consultants do not rely on the GA manual Sound Transmission Class ratings, but use laboratory test reports (multiple reports when available). We may also supplement the lab test reports with field test reports and calculations. Our goal is to determine the most likely average rating for a wall or floor-ceiling. STC tests, even in a laboratory, are not perfectly repeatable. The same wall can be tested in five different labs with five different results. The same wall can be tested multiple times in the same lab and yield different results. Wall construction isn’t perfect and the test method isn’t perfect. Multiple tests of the same wall usually follow more or less a bell curve distribution.     The Gypsum Association categorizes a partition based on one lab test result. The GA categories are typically STC 45-49, 50-54, 55-59, etc. The STC range given by GA is not the range of STC test results for a particular wall. It is simply the category that GA has assigned that wall to. GA gives no indication whether a particular wall falls at the low or high end of that category and a 5-point difference in STC ratings is significant. Unless you research and find the specific lab test referenced by Gypsum Association, you won’t know if your wall’s test is at the high end or the low end of the GA category. Partitions...
Cushioned Vinyl Floor Test – Time Lapse

Cushioned Vinyl Floor Test – Time Lapse

Vinyl flooring options have expanded in recent years to include finishes that mimic the appearance of tile and hardwood. These materials have become popular in multifamily condominium and rental apartment markets, and hospital and healthcare facilities (long term care, hospice, etc.) due to the attractive cost and low maintenance. As acoustical consultants, we evaluate flooring materials as they relate to sounds in the room and impact noise transmission between rooms/units. Hard floors transmit impact noise more easily to the room below, while softer materials like carpet can reduce impact noise transmission. Cushioned vinyl can also result in less noise from footfall, cart traffic, etc., in the room above, which is advantageous in hospital patient rooms and corridors. This is beneficial to both patients and hospital staff. To help improve the impact noise isolation performance of their products and make them more attractive in the market place, flooring manufacturers have been adding integral resilient underlayments and pads to vinyl flooring. These underlayments are usually made of rubber or foam. While these materials do reduce impact noise transmission, our clients expressed concern as to how the material will be affected by heavy furniture, and if permanent marking or imprints will be left on the surface. We tested Ecore’s Forest Rx Vinyl Flooring, by placing a metal desk on a product sample for more than three weeks. The foot of the desk left a deep impression in the vinyl. As we removed the desk from the sample, we recorded a time lapse of the product sample/desk impression. See the video, below. We stopped our time lapse a little over seven hours. While the indent...
Avoid CrossFit Noise Complaints

Avoid CrossFit Noise Complaints

CrossFit Gym Noise High Impact workouts – such as CrossFit and other high intensity Boot Camp style strength and conditioning programs – are gaining in popularity throughout the country. Neighborhood gyms, which were once quiet retreats where clients worked out independently on treadmills with their headphones on, are now social hubs overflowing with people, activity, and loud music. These modern gyms have become one of the biggest sources of noise complaints we see in retail and multifamily buildings. Vibration from dropping weights, medicine balls bouncing off of walls, and the bass rumble of the thumping music can travel into adjoining spaces, even from stand-alone facilities. Shouts, clangs and extremely loud rock and hip hop music are the norm. In multi-family buildings, the noise and vibrations can travel long distances and be heard (and sometimes felt) many floors away. While these workouts are intended to push the limits of the human body, they are also pushing neighbors to the limits of their sanity. We work with gym owners, fitness centers, property managers and tenants, to reduce noise intrusion from gyms, whether it is new construction or an existing facility. Solving Exercise Noise Wave Engineering will evaluate your new project and can perform extensive testing and evaluation of existing conditions to give you a realistic picture of the solution, and how much improvement is possible. Sound Isolation can be improved to counteract the effects of loud music and amplified instruction on neighboring tenants. We can evaluate walls, floors and ceilings to determine where money is best spent to reduce sound and vibration. Don’t be a weakling – let Wave Engineering help...
STC Testing to Evaluate Privacy Concerns

STC Testing to Evaluate Privacy Concerns

What is Noise Intrusion? Noise is typically defined as any unwanted sound. Unwanted sound can distract us from our daily lives (sleep, work, and personal time). While poor sound isolation is often attributed to noises we don’t want to hear, it can also result in sounds we don’t want heard. This can occur in Medical Office Buildings (MOB) where HIPAA speech privacy requirements dictate patient-doctor conversations remain private. Federal and State governments also have confidentiality requirements for specific spaces in their facilities. In residential multi-family dwellings such as apartments, condominiums, and townhomes, privacy complaints can become a problem that Homeowners Associations (HOAs) must address. Building codes also have minimum sound isolation criteria for multi-family dwellings. Wave Engineering can perform field tests on existing wall and floor-ceiling assemblies (in offices, residential units, townhomes, etc.). We then use the test data to identify the problem and recommend solutions. Sound Transmission Class – STC Tests The Sound Transmission Class (STC) is a single-number rating used to quantify the sound isolation of a wall or floor-ceiling assembly. The higher the STC, the better the partition is at reducing sound transmission between spaces. STC tests are usually performed in an acoustic laboratory. In an existing building, Apparent Sound Transmission Class (ASTC) tests are performed. ASTC tests require us to generate loud pink noise on one side of the partition, and to measure the sound level on both sides.  We must also measure reverberation time on receiving side.  A typical test takes one to two hours to complete.   For more information on the ASTC test services Wave Engineering offers, please visit our ASTC Services...