New ADA Assistive Listening System Requirements
Most people who work in the construction industry are aware of the Americans with Disabilities Act of 1990 (commonly referred to as the ADA) and the general impacts it has on how buildings are constructed. On September 15, 2010 the Department of Justice published a series of revised regulations. One section of these updates deals with requirements for ADA Assistive Listening Systems for persons who have hearing disabilities. It’s a subtle change, but a big deal. (more)
Corporate Videoconference Guidelines & Recommendations – Part 1
Teleconferencing requires hearing the voice, so it should follow that videoconferencing requires seeing the people, right? Not so much. Videoconferencing actually requires a finer level of detail – it requires seeing the eyes. Why? We communicate with our eyes. If you cannot clearly see the eyes of the communicator, then you might as well be on a teleconference. This is why web quality video has become unacceptable for many types of corporate communication. Even more difficult are large spaces such as boardrooms or corporate auditoriums. The size of these spaces alone presents a real challenge to the video conferencing system, making it ever more difficult to see the eyes. “So what?” you say. Well, the eventual reality is that without seeing the eyes, users will eventually avoid the technology altogether. (more)
I recently attended concerts at two out-of-state prestigious university level music schools, and from a noise control point of view, the auditoria couldn’t have been more different. While the room acoustics of both halls were superb, the background noise level in one was quite distracting. (more)
Video Wall Design Considerations for Corporate Webcast Auditoriums
Out of curiosity, we asked one of our current clients what made them pick Acoustics By Design to be their audio-video consultant for their corporate webcast auditorium project. We beat out several national AVL consulting firms to get the project, so what made the difference? Well, there were a list of reasons why ABD was the best fit. One reason was that we took time to understand the client’s vision, and that we proposed the concept of a video wall rather than the traditional approach of using several projectors to accomplish their complex webcasts. Cool. So why did we pitch the idea in the first place? (more)
Analog vs. Digital Sound Boards | The Top 3 Factors
On practically every project we work on that has a significant sound system, we have a discussion with the stakeholders about whether the main mixing console should be an analog board or a digital board. In a nutshell, we can boil the discussion down to 3 main points… Price, Flexibility, and Ease of Use. Here’s why… (more)
HVAC Noise Is Intruding On My Listening
Being a noise engineer, I’m always on the “listen-out” for cases of poor building acoustics. I find that common offenders are noisy air handling (HVAC) systems. Frequently the public venues are restaurants, hotels and cinemas, and on occasion it’s a location most tragic, a performance space. (more)
Several weeks ago, a client invited me to a rehearsal in their highly reverberant space that ABD was hired to test and correct. I declined, as I already had plans to attend a play that evening at a different facility, and joked that during the performance I’d also be listening to sirens from the main street outside the theater. Nearly every time we attend a performance in this space, we hear sirens going by the building. Sure enough, on cue in Act II, “errrrrreeeeeerrrrrhhh” slices into the hall. My husband and I shake our heads. This is why sound isolation of performance spaces from outside noise intrusion is so important. (more)
Is Technology the Bottom Line for Web Conferencing and Videoconferencing?
Sure, we all agree that the principle of “garbage in garbage out” applies to audio-visual technology. But is “top of the line equipment” the real bottom line for state of the art web conferencing or videoconferencing? Answer: It’s one of the bottom lines, but not the only bottom line. There are a lot of other factors that go into optimizing a space for web or videoconferencing. (more)
Acoustics from the Ancient Amphitheatre to the Modern Arena
In the days of the ancient Romans, crowds would gather by the thousands in the amphitheater to see a wide range of events: public ceremonies honoring brave soldiers, performances of dramatic presentations, or the gruesome games of the gladiators. Although the events were a visual extravaganza, the amphitheater and coliseum were also designed acoustically to allow the entire audience to hear. Fast forward two thousand years, and we still gather in large groups to see college graduations, rock concerts, sporting events, and more. Two of the primary senses that are titillating to the large masses still remain the same: visual and aural stimulation. (more)
Why Your Conference Room Technology May Soon Be Obsolete: Part II
As the VGA connector continues its rapid transition towards obsolescence (referred to in Part I of this post) many people simply assume that using adapters (such as HDMI to VGA) will solve the digital-to-analog connectivity problem. While this may work in the short term, it ignores the looming problem of DRM (Digital Rights Management), a way of encrypting new media to protect against copyright infringement. DRM uses something called HDCP (High Bandwidth Digital Content Protection) to control which devices are allowed to receive the video signal. So how will you know if you’re using digitally protected content? Well, for starters, your adapter will just stop working. (more)
Psychoacoustics: Transient Noise Grabs Attention
Have you ever noticed how some sounds catch your attention and others do not? For example, you are driving down the road thinking of your plans for the day and all of a sudden you hear a squeak in the dashboard. It draws your attention immediately, while the air conditioning fan likely does not. The squeak is intermittent (and likely tonal, but that’s a topic for another blog) and therefore stands out over the more constant sound of the fan. This reaction is similar to vision, where our attention is drawn by moving objects much more so than stationary ones. (more)
Why Techies Buy Audio-Video Gear Online
My church recently decided to upgrade from our old analog mixing board to a brand new digital mixing console. The interesting part of this process was that they did not buy it through a local AV contractor. They purchased the sound board online through a company that specializes in phone and internet box sales. This got me thinking about the trend over the past few years in which more and more Audio Visual end-users purchase equipment from online sources instead of the local dealer or shop. Is this a good thing or a bad thing? And why is this becoming the norm? (more)
The Speaker Shootout at High Noon
Question: How do you assure your client that they are getting the best possible speakers for their Auditorium or Fine Arts Center? Answer: You hold a “speaker shootout”. Recently one of our clients was in this exact situation, so we did just that. We invited several manufacturers of line array speakers to show up, all on the same day, so we could let our client hear the differences in sound quality back and forth in the exact same auditorium they would be installed in. Three different manufacturers arrived, speakers in tow, to hang their line arrays for the shootout. As the client’s AV Consulting Firm, we were there to moderate the shootout and ensure that each manufacturer got a fair shake (clean signal, volume levels, sound power levels, and so on). And then we began. The client had arranged for a group of about 20 listeners and key decision makers to join us for the shootout as a virtual “jury” to help decide which speakers to purchase. May the best speakers win! (more)
Why Your Conference Room Technology May Soon Be Obsolete
You can’t get away from the digital age. It seems like digital technology is everywhere. As Audio-Video designers, the march towards all things digital is having an impact on display technologies as well. Meanwhile, flying under the radar, there is a subtle shift happening in how the average person shows information from a computer onto a projector or display. (more)
If It Sounds Like Noise to You, It May Be “Esion”
Fundamentally, sound is “that which we hear”. What we hear at any given time can greatly influence us. We use sound to communicate, to express warning, fear, pleasure and excitement. Some sounds can relax us and help us fall asleep, while other sounds can distract us and make it more difficult to perform simple tasks. Different sounds can be soothing and pleasing or annoying and irritating. Accordingly, determining “What is sound?” and “What is noise?” can become a highly subjective task. As engineers and scientists, it’s our job to generate generalized models that have a high level of correlation to humans (or to specific populations). (more)
Space Savers | Acoustical Engineering for Gymnatoriums and Cafetoriums
It certainly isn’t a new idea… How do we maximize our space and minimize our cost without the loss of function? Surely this is the major driver behind ideas like the gymnatorium or the cafetorium. We’ve all seen them, most likely they were in the schools that we attended. They consist of a stage at one end of the room or tucked away in the corner. So, do these budget savers really work like they are supposed to? (more)
White Space Update for Wireless Microphones
Several months ago (10-13-08) I wrote about the current state of the wireless microphone frequency spectrum and how the actions of congress and the FCC are shaping the future of wireless technology. Well, several notable updates and changes have been made since that time. You may recall that February 17, 2009, was the date set for the transition to DTV (Digital TV). Congress (in all its wisdom) decided that it would extend the deadline to June 12, 2009. (more)
The Leaky Bucket | How Sound Escapes
Blocking sound is often analogized to plugging the holes in a leaky bucket. If you plug up all the bucket holes except one, the bucket is still going to drain. In acoustics, an outstanding partition design will not adequately block sound if holes and weak spots exist where sound can find its way through. (more)
Elbows vs. Sound Attenuators: Interchangeable?
It is common belief that a series of elbows near an air handling unit (AHU) can accomplish the same insertion loss as a manufactured duct sound attenuator. It’s true that elbows are less expensive than sound attenuators, but what acoustical performance is really achieved with this “low cost” substitution?
Let’s compare the two designs. Using the tables presented in the 2007 ASHRAE Handbook – HVAC Applications, for any type of elbow (round, rectangular, acoustically lined or not), the width of an elbow (in the plane that it turns) must equal or exceed 30 inches to get ANY insertion loss at 63 Hz. A 30 inch wide elbow provides only 1 dB of insertion loss (IL) at 125 Hz . These two frequencies are typically of concern when reducing sound from AHUs.
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