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ID No: #148
22.02.2008 00:00

Özhan Atalay

Outside Noise and Impacts on Sound

Outside Noise and Impacts on Sound of a High End Audio System

Noise

Noise can be described as unwanted sounds. Someone who is exposed to noise for a long time may have serious illness on hearing sense. Noise affects our life quality, obstructs our fast reaction capabilities and our concentration. Noise may cause sleeplessness and stress.

Background noise increases year by year and influences human health in big cities. Noiseless environment provides the feelings of presence, peace, coolness and gentleness; hence a lot of people go to countryside on holidays. Considering the noise is the first step to fight against it.

Noise vs. Sound
Noise can also be described as the accumulation of so many unwanted frequencies. For instance white noise is similar to the sound in FM radios or TVs when the channel tuning was not done. White Noise is the accumulation of plenty of different frequency of signals, thats why partially masks required sounds. Another kind of noise is the pink noise. Pink noise is similar to white noise but with stronger lower frequencies.

Lets assume that we are in listening room and a kid crying in the garden. If we turn on the air condition in slow mode, the kids cry disappears although the a. conditioners noise is much less then the kid. The reason for that is air condition provides white sound which can be a combination of one thousand different kids.

Imagine that two people talks in front of us. Our brain will easily perceive both of their sounds. If the third person added to talk, it will become difficult for our brain to differentiate all of them and most probably the brain will go towards one person only and will not consider the other two. Assume that another one thousand people is added to that chat. It will be impossible for brain to distinguish any individual persons sound. The white noise of an air condition is quite similar to the sound of 1000 people. It is obvious that the kids cry will add one more. 1000 or 1001 does it matter for our brain, NO! Thats why the kids cry disappeared.

Years ago, we climbed to a mountain which was 2000 meters height. We were only two people and nobody existed around. We wanted to watch the city from distance but realized that a noise was coming from distant. We first presumed a plane or an earth quake but realised later that the noise of the city itself. When we were inside of that city, that noise was not exist even though it was such powerful that can be heard from one kilometre.

We may measure the impact of outside noise. If you have a Radio Shack Decibel Meter, go out to balcony in any time in a day and measure the noise in C Weightening mode. Your meter will show a noise although there is no particular noise. You dont realise the greatness of the noise but the electronic meter does. Make the same measure after 24:00 oclock; you will see that much lower.

For instance the noise measurements are as follows in Istanbul Kiziltoprak on 28/2/2004
Radio Shack Digital Decibel Meter Slow Response C Weightening
at 12:15 Hours In Balcony 85 dB
at 12:15 Hours in listening room, double glass windows closed 55 dB (85-55=30/3=10 times less)
at 12:15 Hours in listening room next to the live playing piano 68 dB

In other words, the outside noise is similar to 5,6 pianos sound. (85-68=17/3= 5,6). There is no particular evident noise at balcony but the noise is similar to 5,6 pianos. Interesting isnt it. If you listen at a live piano in balcony, 1/5 of its sound is disturbed and cancelled by the noise.

At 01:15 Hours in Balcony 60 dB (8 times less than day time)
At 01:15 Hours in listening room lesser than the limit of the dB meter

At 01:15 oclock in listening room, Klipsch Sub Woofers buzz is clearly evident in spite it was never exist in day time. If that buzz was a detail in music, would not be heard during the day time.

Real system run by above amplifiers (Cary 1610 mostly) Ugh..

Noise and Listening Music
Our brain filters the continuous sound attacks from outside and obtains better life for ourselves. Listening music in such environments may be problematic, considerable frequencies and details are lost in that garbage particularly the soundstage information.

In high noise environments, our brain will raise the hearing level to upper level and we should be in a position of turning the volume up. Thats why we turn the volume down in night but achieve the same satisfaction (not only to consider our crazy neighbour in upstairs :-)))

Some audiophiles consider that the electricity is much clear and less distorted in the night, so the sound quality is better. I am not agreeing with that. Electricity is more in usage during the night, thats why electricity companies charge more for evening usage. More usage means more pollution.

You may have much better sounds from the same system if you can obstruct the outside noise. Several factors will help as dual glass windows, special fibre or rough surface wall papers or special kind of porous covering material, keeping the windows closed, thick curtains on windows, particularly by making the critical listening sessions in the night. Due to hi-end is hidden in micro details, everything but especially the soundstage will be enlarged and expand


Özhan Atalay

February 2004
Published at Volume Magazine - September/October 2008 Issue