It all sounds great, working from home, a relaxed atmosphere your dog/cat at your side and then you take a call from an important client and they say “Wow! Are you on a speaker phone? All I hear is the echo of your voice and cars outside.” Very annoying and embarrassing indeed. This folks is reverberation of sound, also known as echo and it is the new pain in your arse.
Gig Economy guys and gals and those that work from home know all too well – you gotta get this echo under control. Modern home office spaces feature large open areas and many hard surfaces such as glass, tile, wood or concrete. Echo can make the most attractive and comfortable spaces to work unbearable. There are many creative and appealing solutions to avoid or resolve acoustical problems. To optimize the acoustics of a room, it’s important to understand a little about the science behind acoustics to determine the best solution for your application.
When a gong is struck with a mallet or striker, it creates vibrations. Strummed or plucked strings on a guitar create vibrations. Vocal cords vibrate, resulting in speech. These vibrations create a sound wave that travels through the air in the form of small changes in atmospheric pressure, alternating above and below the static pressure. Loudness is the physical response to sound pressure and intensity. Our ears vibrate similarly to the original sources of the vibration, allowing us to hear different sounds.
The quality of sound is determined by frequency. Measured in units of hertz (Hz), frequency is the number of complete cycles of vibration above and below the static pressure in a unit of time. The human ear detects pressure changes at a rate of 16 times per second or more. Direct sound travels from the source directly to the ear. Indirect sound is reflected from a surrounding surface. Portions of sound energy are absorbed when the sound is reflected off a surface. Reflection of sound signals can enhance the quality and strength of speech and music. Delayed reflections or multiple sounds reflected simultaneously can cause echoes, which reduces speech intelligibility.
Sound loses part of its energy when it is reflected from a surface. The portion of energy that is not reflected, is sound absorption coefficient. If a surface reflects 80 percent of the sound energy, its sound absorptioncoefficient is 0.20.
If you clap your hands once in a room, the sound will continue to reflect on the surfaces until it loses enough energy from absorption and dies out. This is described as the reverberation time, which is identified as the number of seconds required for a sound to die out to one millionth of its original energy (60 dB).
A room’s reverberation time is influenced by the dimensions and absorptive properties of the surfaces and other content in the room. Reverberation impacts speech intelligibility, enjoyment of music and overall noisiness of a room. Optimum reverberation time is based on the size and use of a room.
SONEX-Online offers glue-up wall and ceiling panels and baffles made of fire resistant melamine foam. Melamine foam does one thing very well – absorb sound. The maximum noise reduction potential when treating a room with SONEX products is from 4 to 6 decibels, resulting in a noise level reduction of 20 to 30 percent ! How much do you use? Less than you may think. A good rule of thumb is 20 to 25% of the hard surfaces in a space need treated with a good sound absorbing material. That typically translates to the floor print of a space. First, determine the square footage of space so you know how much material you need. Then decide where to apply the material (walls, ceilings or suspended baffles).
We recommend SONEX-Valueline glue up panels for walls and ceilings in the 1-7/8″ thickness. SONEX-Valueline has a very high level of absorption at 0.95 NRC and the natural white or natural gray options are the most cost effective solutions we have seen for home applications. It has a whopping 1.0 NRC at 2″ thickness, it doesn’t get much better than that. The SONEX-Basix glue up wall and ceiling panels are also great options with an NRC of 0.90. All Sonex panels are installed very easily, they are lightweight, cut with a utility knife and only requires adhesive that is water based to install. If you’re not sure how much to use, just start with one box, if that is not enough, simply add more material until you are pleased and satisfied with the sound quality.
So what are you waiting for – go ahead and get on that conference call, web cast or webinar, it is gonna sound great!