Friday 27 May 2011

How To Set Up A White Noise Generator

Today's weather: High = 22 Low = 17
Cloudy

What follows are step-by-step instructions for anyone who would like to configure a white noise generator. I did this last night as a trial run and it worked beyond my expectations. This is a much better solution than earplugs for cutting out unwanted background noise when sleeping, taking naps, etc.

The only warning I can give about this method is that it's actually TOO effective. That is to say, the backround sounds will be completely masked out to the point where you are generating a pseudo-silence that ends up playing tricks with your brain. The long-term effects of sleeping with a white noise generator are unknown as of yet. For instance, how does this affect dreams? Sometimes dreams will feed off sounds that are actually going on outside. Then again, sometimes not.

If there ever were a genuine emergency requiring the middle of the night, as indicated by some unusual sound, you wouldn't be able to hear it. What you have effectively done is made yourself deaf to ANY background noises that are within the frequency range of your self-configured generator, and that have a decibel level less than or equal to the generator settings.

This is where it can play tricks with the brain. In a normal situation, over time, your brain learns to know which of the enormous volley of background sounds are "safe" and which indicate danger. I can't remember which part of the brain does this, maybe it's the thallamus.

I was a physics major in university, not a biology major.

Anyways, a present example is the downtown place where I live that is right above a subway line. When the subway rumbles underneath, my brain has learned this sound is "safe". Same with car alarms, roaring 250cc scooters, and other repeated sounds. But suppose an unusual fire alarm were to go off, an air-raid siren, or a person blaring into a megaphone outside that some imminent danger were to occur such as a tsunami or typhoon. If this was an unusual sound indicating danger, I'd be jolted out of bed and ready for action.

It's the same idea for people who spend years living near railway lines and don't flinch to the sound of a train siren blaring, but they will immediately jolt out of bed if a thief breaks into the house and causes a squeaking noise on the steps or something like that.

Earplugs would cut down on all sounds but not eliminate them, so a genuine danger sound could still act as a alarm.

Not so with a noise generator. If done effectively, it will actually *eliminate* all sounds by way of the frequency and amplitude masking principle. So it's a fair warning that you will have to rely on other senses in case of an emergency at night, such as touch (someone comes running into the room and shakes you awake), or smell (the smoke from a fire). You realize that by doing this, you will be surrendering to a sleep without any emergencies. If the thief comes breaking into your house at night, you wouldn't have a clue.

But how often does any of that happen? I can't recall a single time in the last 30 years when a genuine emergency has happened at night where a sense of keen hearing would have saved me from a disaster. There have been multiple false alarms when I wished I wasn't such a light sleeper.

To make a long story short, the noise generator is a risk, but it's worth doing in a city like Shanghai that is perpetually noisy, most of it being useless noise pollution. Let's just cut to the chase and discuss how to do this

1. Download a noise generator program from the internet. I highly recommend 'Soundmasker Deluxe 7.0' which you can find by simply doing a web search. Also, download a key generator to activate the program to make continuous noise clips. Unless you just want short 10 minute clips (I dind't think you did). I wouldn't bother with pre-recorded white noise MP3 clips as they tend to be either low-quality, they are too short, or they play with loops that make discontinuous recordings. Best to get a generator as you can then program the frequencies and amplitudes to your liking.

2. Set up a frequency range, by configuring the generator to mask the desired frequencies. What I've done is set it up to do bass masking, as the chronic problem is the rumbling subways and the illegal loud 250cc scooters zipping around outside. The treble isn't masked as much, so I can still hear my alarm clock in the morning. If treble bothers you, then set up a high frequency mask. If all sounds bother you, then do a full frequency scan.

3. Configure the masking to be either static or dynamic. That is, you can play a steady stream of unchanging frequencies and amplitudes, or you can vary either or the two or both. For example, beach waves work on a periodic function for amplitude (louder, softer, etc.) and they also vary frequencies, usually with a logarithmic sweep function. The advanced programs can do all of this.

4. Set up an alarm clock. The easiest way is to just program the noise generator to stop playing white noise when you want to wake up, and thenb play something else, i.e. music files. Alternatively, you can program a separate alarm clock outside the range of your generator

5. Set up the maximum amplitude. The way to do this is wait for when the loudest background noise occurs, within a certain frequency, and then turn up the white noise generator so it is slightly louder.

6. Choose your delivery system. There are multiple ways to do this. Last night I simply put headphones to my computer and slept that way. But if the computer falls over or gets damaged while sleeping, etc. it may not be the best idea. So I'm now recording and downloading a massive MP3 file into my blackberry device and will try that one tonight. Another plan might be to use actual speakers hooked up to a computer which generates the external white noise, and then combine it with earplugs.

7. Decide how long you want to run this. In order to deal with the emergency issues, it's possible that you could do a shorter version (say 60 minutes) in order for you to fall asleep, and then the program shuts off during the night. If it turns out that noises cause you to wake up, then you might want to have the program running all night.

As per the above warning, who knows what the long term effects are of doing this, but I'm eager to keep trying the experiment if the first success was any indication of how well this is working out.

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