Introduction by SweatLifeNYC.com:
Alan Fierstein is a hidden hero in the fitness world here in NYC, working behind-the-scenes to ensure that so many of our favorite fitness studios are able to open their doors without disturbing the neighborhood. He is responsible for soundproofing the fitness studios we frequent every day - helping to guard against complaints about thumping music, and minimizing the sounds of jumping bodies and weights hitting the ground over and over. Alan is keeping the fitness party going, so to speak. Here, he tells us more about his craft.

I've been working with gyms, dance studios, and places that play loud music in NYC since I started Acoustilog over 40 years ago, working for such businesses to help them soundproof - as well as for their neighbors, who may have complaints about the noise.

I've always been into electronics and recording, even as far back as high school when I used to record with my band. After working in recording studios, I developed a device for measuring room acoustics, and people started asking me to consult for them. It wasn't my idea to become a consultant; it occurred due to popular demand.

Many people don't realize that there are two types of acoustics of rooms: internal and external. "Internal" refers to the sound in the room itself - is it too "echoey," "live," or "reverberant?" Or not live enough, meaning too "dead?" "External" acoustics is about stopping sound from being transmitted in or out - through the walls, ceiling, and floor, or through openings.

Then there's the question of vibration.

All sound is vibration and some vibration is sound, but when it's in a solid material it's more likely to be described as vibration. Vibration in the air we call sound. However, that pumping or throbbing sound that you can feel in your chest - that many people call vibration - is really just a low-frequency sound, commonly called bass.

Sound and vibration can be airborne or structure-borne. Airborne sound is carried totally or mostly through the air, and is often caused by music, but not always. Structure-borne sound is carried totally or mostly through the body of a building, and is often caused by an impact against some part of the building. A dropped barbell is an obvious source of structure-borne noise, but people also create such sounds when they land on the floor during their exercise routines. While airborne sound commonly comes from speakers playing loud music, speakers mounted to the wall or ceiling may generate structure-borne sound as well.

When weights are dropped, they shake the floor - which in turn shakes the building, and not just the floor below, but sometimes the floor above and even floors above that one. When music is played, the sound can enter the ceiling, walls, and floors and travel in all directions as well. Contrary to popular myth, sound is not affected by gravity. It doesn't go "up" nor does it go "down." It travels in all directions unless stopped by some means.

If your gym happens to be located in a building where there is sufficient natural soundproofing, you are in luck. Otherwise, you will need to add soundproofing, which can get expensive. The best choice for a noisy gym is in a building that has no residential neighbors nearby, and that includes in buildings next door and behind. Even a one-story building can be problematic if there are taller buildings that overlook your roof; sound can exit the roof and then enter the windows of those buildings.

In order to implement effective controls, it is imperative to inspect and test the location in question. There is no "one size fits all" soundproofing method or material that can be quoted "by the square foot." Reducing airborne sound requires stronger or additional barriers such as walls, floors, and ceilings, often with insulation. Structure-borne sound and vibration is reduced by introducing a "vibration-break" in the path, sometimes using floating floors. The specific construction and the specific intended use must dictate the remedy.

When I am called by a gym's neighbors with a noise complaint, I first suggest the cooperative approach. I urge them to contact the gym and arrange a convenient time for a test. I then determine where and how the sound is transmitted, and how much vibration is traveling, as well. If, on the other hand, the gym will not cooperate, I do a clandestine test. The benefit of this approach, from the disturbed neighbor's point of view, is that I get a real life example of how much sound or vibration the gym is making while the gym is unaware they are being monitored. This sound or vibration is then compared to the allowable levels in that location. I then write a report with conclusions and sometimes suggestions.

Sometimes it is a commercial neighbor who is disturbed. I have seen examples in which neighbors have claimed that the gym's vibration has caused structural damage, or has damaged their business.

And sometimes I am called in by the landlord; a landlord will often insist that a gym soundproof before it opens its doors.

When potentially noisy businesses open up without proper planning, disputes and even lawsuits can develop. I am often called in by attorneys to document sounds or vibration levels. When cases like this get really heated up they can go to court, which wastes a lot of money, as none of those legal fees go toward actual soundproofing. Even court cases usually end up settling, with the gym having to do soundproofing of some sort. It saves a lot of time and money to do it right the first time!

All too often I encounter gross misinformation which has to be corrected, and I don't like being the messenger that gets shot for bringing the bad news. I much prefer to uncover these situations ahead of time, before tens of thousands of dollars are wasted on some contractor's copy of what may have worked in some other place across town, or an inexperienced consultant's idea that was taken out of a book (or even from one of my previous reports!). What may have worked elsewhere is irrelevant, and each studio is different. What is needed is a custom analysis and the right soundproofing for that facility.

Each location is different, and each studio has different needs, but if you put in the work from the start to soundproof your studio, you will never run into problems. No one wants to have to turn down the music!