How to sound proof HTS room ?

[m4w]

This depends on the sound absorption you are looking for.

The acoustical property of a material is measured by it's sound absorption coefficients as various frequencies. The absorption coefficient of a material is the fraction of the random sound power which is absorbed, or otherwise not reflected. Generally, the coefficient is measured at the preferred octave frequencies over the range of at least 125Hz - 4kHz. When a material has a coefficient of 1.0, it absorbs all sound between these frequencies.

Generally the sound absorption coefficient should be as follows as shown various frequencies.

125Hz - ~0.1
250Hz - ~0.2
500Hz - ~0.3
1000Hz - ~0.4
2000Hz - ~0.6
4000Hz - ~0.9

Wood board does not have good sound absorption coefficients. For frequency range from 250Hz to 500Hz it is 0.10, and 1000Hz to 2000Hz it is 0.30. Though it will provide some absorption, it is not ideal. Look for a material that has the sound absorption coefficients as near the figures I have shown above.

Cheers

I've looked up Fibrecrete's NRC values and they have a product that comes close to the values you mentioned (with a 50mm airgap tho):

50mm-320

125Hz - ~0.17
250Hz - ~0.29
500Hz - ~0.58
1000Hz - ~0.64
2000Hz - ~0.64
4000Hz - ~0.91

This apparently works out to a 0.80 NRC value. They have other boards that are supposed to be 0.80 and 1.0 as well. Indicative chart:

25mm-320 (w/ 50mm glasswool)

125Hz - ~0.31
250Hz - ~0.72
500Hz - ~0.87
1000Hz - ~0.96
2000Hz - ~0.81
4000Hz - ~1.00

NRC = 0.80


What do you think?

 

[venkatcr]

The 50mm-320 looks good.

cheers

 

[ssge]

Hello,
Thanks for the details and examples.

I stay on a busy street with the master bedroom having a wall towards the road/street. There is a large 5 feet - 7 feet glass window in the wall with sliding window panes. It has two window-panes that cover the window, each of size 5 feet by 3.5 feet single glass that slides either way.

Mostly its the sound of passing vehicles/honking (i.e low frequency sound) and people chit-chatting while they walk at night.
Day time noise is fine as I am busy with work, but night time street noise wrecks havoc causing sleeplessness.
So basically, the problem seem to be the windows as they allow sound to come in.
Its my own house, so I can make any changes I want, and am ready to cover the windows fully at night with suitable material if the sound can stop to allow peaceful sleep. Day time, that cover can be removed.

Questions -
1) I suppose this will be for sound blocking at the windows (or will sound absorption also help)?
2) Which possible product(s) and setup will be suitable for preventing the street noise at night?

Thanks a lot in advance.

 

[amangujral06]

I am an architect, so let me give you the most simplest of solution to a very common problem.

Your sliding window is the only culprit here. if there are gaps, visible or not within the sliding mechanism, it will let in sound. Low or high frequencies make no difference. The simplest solution here is to get a new window. This time get a sound proof , double glazed window. Sliding or regular is upto you. A sound proof window will completely eliminate you problem permanently. no other treatments needed.

1)sound absorbtion works for the sounds you will make inside your room. like getting ceiling to floor curtains. Carpeting the floor. It will stop the Echo of the sound entering the room as well, but it wont stop the sound.
2) Get fenesta windows if you can afford their products. world class products, but expensive. for half the price of fenesta, there are several other not so famous name brands that you will find at hardware markets in your city.

there are several other temporary fixes but i cant tell you those unless i see the state of your window, thickness of glass, aging of rubber seal, provision in the frame for additional rubber seal . etc.

 

[redblue]

2) Which possible product(s) and setup will be suitable for preventing the street noise at night?

Thanks a lot in advance.

Use ear plugs. To prevent fatigue of your ear canals upon waking up, use the soft foam type. Once you experience 30+dB noise reduction, you'll be shocked. Earplugs have little effect on low frequencies, but thankfully they are the ones that don't disturb sleep.

 

[Naturelover]

I am very sensitive to noise. I replaced my regular aluminium sliding windows with Lingel brand UPVC single glazed windows. It made a huge difference. The noise level in my locality is not very high so I was advised, rightly, to go for single glazing. As has been said above, there are a lot of brands so it will be good to get some professional advice.