Blog Archive

Monday, August 7, 2017

Quora: White Noise - Do people hear voices coming from their white noise sound machines?

5 Answers


Bill McDonald
Yes, and you can also see faces in random TV static.
The human mind will find a pattern when none exists, or where even a fraction of a pattern is there.

A note on the repetition part:

Many white noise circuits use a pseudo random sequence generator, which seems to generate random numbers, but actually repeats a pretty long sequence (long in electronic terms).  That sequence can be short in terms of the human audio system.

Oh, and a shorter sequence will be slightly cheaper. So there is an incentive to make the sequence as short as it can be before people causally notice the white noise seems to repeat...

Another thing about pseudo-random generators - they will generate all but one possible combination of digital words. A typical version will generate about 32,000 digital words.  Some sequences of these digital words will result in something that sounds like part of a syllable. So you could easily have 50 or more syllable fragments in the actual sound, being repeated.

This is roughly analogous to trying every possible combination on a combination lock.

So yeah, white noise will sometimes sound like speech.


There is another possibility, and that is a strong nearby transmitter (CB. police, amateur radio, pirate radio station, walkie-talkies, etc.) can interfere and you will hear distorted (or sometimes clear) voice come through.  Radio operators often repeat phrases when there is communication difficulty.

This occurs with all sorts of consumer radios.  Older TV sets used to be able to hear the analog (AMPS) cell phones signals on the UHF bands.  A strong signal will "break through" into many radios.  You may have drive past a radio station that is near a road, and had the nearby station's signal override a different station you were listening to.  (This would happen often when driving past the old KKHI station next to US 101 near San Carlos, California.  It can still happen when driving near KGO - AM 810 KHz (50,000 watts) on the Dumbarton bridge causeway in Fremont, California.



Frank Goad
In a semi-sleep/dream state, your mind will inject weird stuff, just like in a full dream state. We can be in a semi-state, yet feel like we're actually awake and still get some input from our surroundings. I have talked to my wife in a nascent dream, yet knew the dog jumped on the bed, that the cat was bugging her for food, etc., and she confirmed these activities. She's a licensed counselor and therapist with a quarter-century under her belt and confirmed that a variety of things can cause that (meds, stress, lack of sleep, etc.).

Most white noise machines create a sound frequency through synthesis, not from recordings; a single, simple, cheap chip is all that's needed. Recording requires memory which means more complex designs and expense; a chip is super-simple. So, it's likely what you heard was a reflection of some news story or a book or simply just random stuff our subconscious coughs up. I'm surprised it didn't say, "Number nine, number nine, number nine" or, "Is that a penguin on the telly?"


I've been sleeping with a white noise sound machine for over twenty years. But on one occasion, and one occasion only, I very clearly and distinctly heard a sentence repeat itself three times: "A billion crimes will be committed. A billion crimes will be committed. A billion crimes will be committed."

It was very creepy, and didn't seem to be anything from a radio or cordless phone. And I can't imagine why my imagination would come up with that.


Joe Munro
These could be caused by hypnogogic or hypnapompic hallucinations. These hallucinations can occur on the cusp of consciousness as you fall asleep or wake from sleep. Experiences can be tactile, auditory, visual or olfactory. They are more common in schizophrenia but will be experienced by most of us at some point in our lives and for the most part are completely harmless.

Joe Geronimo Martinez
I've heard the words "Take care and beware the evil one is watching you" repeated, but when I was younger. This was not from a white noise machine but a radio, in the old days you got a lot more random static.The radio was on, but not tuned to a station: I found that helped me concentrate better than silence. At the time I was investigating the properties of cosine 1/3 which is something that still scares me.
I put it down to anxiety and overwork, but a lot of weird stuff happens