Soundproofing, Noise Tolerances, Noise Reduction and STC Values, Part 2

STC Values and Noise Tolerance Levels

The graph below shows the soundproofing required to make the noise level tolerable. We then define each STC value range and describe how people will best be served in terms of their Noise Tolerance Levels and noise sensitivity in order to make the environment quieter.

Graph demonstrating the level of soundproofing required to make the noise level tolerable.

The groupings below all assume there is at least a moderate noise level involved.

STC Values Below 32

The Noise Tolerance Level 1 and 2 groups would be happy with this level until the noise level gets fairly high, moving more of the second group into the third level as it gets noisier.  In a reasonably quiet environment few people are affected or even notice noise problems and noise reduction would not seem to be a necessity.

STC Values to 38

Many people would say this is enough soundproofing.  Soundproofing would, in that sense, move most people down one noise tolerance level, but a bigger noise problem would not. 

Soundproofing to achieve STC values to 36 would only tease with a low noise tolerance, and while a noise reduction improvement would be made, it would not be enough to change anything.  STC 36 is an excellent level for someone living in a moderately quiet area that really appreciates the quiet.  It will shut out much of the typical neighborhood noises.  This is the first STC value that can exhibit the special oasis effects one can get when creating a quiet environment.  It almost approaches sound studio quiet, when not in a noisy area.

STC Values to 42

When we get to this STC value, this will move most people one Noise Tolerance level.  For those still in the most sensitive group, it will still be frustrating.  Noise reduction can be costly getting to this level, and yet it is not quite good enough.  Sometimes, soundproofing to get to STC 42 can be aggravating because it is almost all the noise reduction you need but not quite.  Many of the noise problems are gone, but the serious ones may still linger and annoy.  Here, in a moderate noise environment you can get a sense of sound studio quiet.

STC Values to 48

Soundproofing to this STC value moves most people two Noise Tolerance Levels.  Levels 1 and 2 now consider all their noise problems resolved.  To still be in Level 3 is unusual.  Either the noise levels are exceptionally loud or the sensitivity levels of the person are very high.  Even those in Noise Tolerance Level 3 will still be “mostly happy” with the soundproofing.  Most or all of the noise problem is reduced to a very tolerable level.  If the person is still at Noise Tolerance Level 4, then the noise level is truly exceptional and the person is very sensitive and likely very stressed in general. 

In most cases this level of soundproofing creates sound studio quiet, which is an amazing and wonderful thing to experience and to live in such a quiet environment would satisfy most people.

STC Values Above 52

Studio sound quality quiet is achieved with soundproofing.  When you enter a room that is at this level you immediately relax.  You seriously de-stress (at least markedly) regardless of how stressed you may be.  If you live in this environment for even a little while, you will be hooked on how great it is to live in a quiet soundproofed environment. 

In homes where we have created a room that has these levels of quiet with soundproofing, the residents find themselves spending all available time in the quieter room because they are so comfortable and relaxed.  If this is not the case with this STC value, then there are some serious external noise problems.  For example, the room could be located a few feet from a railroad crossing that is right on the airport takeoff path and right beside a huge dog kennel.  Even then, anyone that would have even mildly considered living there in the first place would still be amazed at how quiet it has now become with soundproofing.

A globe of the earth wearing headphones.  It is possible to soundproof all noise.

Contributing Soundproofing Expert:

Randy Brown
Soundproof Windows, Inc.