| Isn't it amazing how much sound we're | | | | place of soundproof solitude are the low |
| bombarded with everyday? We love to find a | | | | frequencies below 125Hz. This is the realm of |
| quiet moment where we are not acoustically | | | | the worst sound of all. |
| assaulted by people, equipment, traffic, | | | | |
| stereos, neighbors, cell phones, and on and | | | | There would seem to be a need to set |
| on. It's hard to find that quiet moment, and | | | | standards for healthy living that describe |
| perhaps even harder to find that soundproof | | | | how to insulate yourself from such noise. In |
| place. Sound levels are so intense that many | | | | fact, there is a standard that measures a |
| walls and building materials just don't stop | | | | structure's ability to hold back sound. It is |
| the sound satisfactorily. | | | | called STC, which stands for Sound |
| | | | Transmission Coefficient, and is the most |
| Think of it. How often are you bothered by | | | | recognized and discussed sound isolation term |
| noise from the person in the room next door, | | | | in North America. |
| even though the door's shut? Have a music | | | | |
| student in the house? Dad like to watch | | | | Building codes will dictate what STC level a |
| movies late at night? How about the neighbors | | | | building needs to have. A new condo, town |
| having yet another party? | | | | home or apartment will have to comply to |
| | | | these building codes and build walls, |
| How in the world do we cope? It's no wonder | | | | ceilings and floors that meet these STC |
| that Ben Affleck slept in a soundproof | | | | requirements. If this is so, how come I can |
| sensory deprivation chamber in the movie | | | | hear my neighbor? Why is my new condo so |
| Davedevil. But of all the noise that we | | | | noisy? After all, the structure is built to |
| retreat from there's one that's the worst of | | | | code. |
| all. Bass. It's the worst because it's the | | | | |
| hardest to stop. In the acoustics industry, | | | | The reason that new structures are still |
| "bass" is known as low frequency sound. It's | | | | noisy is because of the STC standard itself. |
| the boom-boom music sound you hear coming up | | | | STC does not measure any of the worst sound |
| behind you while driving. You hear it long | | | | of all. It stops measuring at 125Hz... |
| before you see the car that's creating it. | | | | exactly where the worst sound starts. So you |
| Low frequencies are the jets flying overhead | | | | have a high STC wall that meets code, but |
| if you're near a major airport. | | | | sounds terrible. Great. |
| | | | |
| This is the worst sound of all because it | | | | There is a need to change this STC standard |
| assaults from long distance. It penetrates | | | | to include these low frequencies. They do |
| normal building walls and ceilings. Low | | | | this already in Europe and Australia. In the |
| frequencies are the largest and generally the | | | | meantime, what can you do? |
| most powerful sound waves we come up against | | | | |
| daily. They are hard to escape. | | | | Look for building techniques that have been |
| Paradoxically, the low frequency "bass" is | | | | tested below 125 Hz. Good performance below |
| what is being sought more and more in home | | | | 125Hz. will help you a lot. Be aware of |
| theaters, bands, and music systems. So our | | | | products like resilient channel, "sound" |
| dilemma is only going to get worse. | | | | boards, foams, tapes, clips and especially |
| | | | mass loaded vinyl (MLV). These products won't |
| The "volume" level of sound is measured in | | | | help you in these critical low frequencies. |
| Decibels (dB). The frequency of sound (bass, | | | | Consider materials that "damp" the sound |
| midrange, treble, low notes, high notes, etc) | | | | vibration. These types of products are |
| is measured in Hertz (Hz). The sounds that | | | | generally known as visco-elastics and are |
| are most problematic when we retreat to a | | | | most effective with the worst sound of all. |