Design of white noise generator for bathroom??

[Zero999]

Or maybe just a bathroom/shower radio, tuned on AM to no station.

FM radio between stations has a more predictable and uniform hiss.

The problem with that approach is that under certain atmospheric conditions, the radio might pick up distant stations, which are normally undetectable.

You clearly have significant expertise in acoustics, and I very much appreciate your help.  I just put up a general response to everyone, and am hoping you can provide me with more technical information about using white versus pink versus brown noise to mask bathroom sounds.  As I see hear it, there are two nuisance sounds to mask:  urine hitting water or the toilet bowl, and flatulence.  Do you have any information about the frequencies of these two sounds, and thoughts about whether pink noise would mask both.

I enjoy getting both the fun and serious responses I'm getting to my post, but this really is a problem I need to solve.  I'm currently using a small portable white noise generator in my bathroom. Kt's ok, but requires me to turn it on manually each time I use the bathroom.

My wife wants to also have noise generators in two other bathrooms that guests use to ensure they aren't embarrassed if they generate nuisance bathroom sounds.  We don't want to give our guests instruction on how to use little bathroom noise generators, thus a noise generator that comes on automatically would be the best solution.  I'm very good with electrical circuitry, and want to put a noise generator in the ceiling controlled by a motion detector set to run for 10 to 15 minutes.
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Also, based on what you know, how much better sound absorption is there with a solid-core door versus a hollow door?

I've found several schematics on the Internet for building low-voltage white noise generators, but they don't provide me with much information about the frequency or decibels of the sound they create.  There are also hobby kits available on the Internet for low cost, but again they don't identify the sound generated.

Pink noise is normally recommended for masking.

What's wrong with your existing noise generator? Connect it to the lighting circuit, via a suitable fuse and power supply.

[MichiganMark]

Thanks for the advice.  Looking at the Dohm unit, it appears as though its primary purpose is to help with insomnia.  Can it be dialed up enough to mask the bathroom noises.

I've been using a plug-in LectroFan.  It's ok, but if it looses power, it won't come back on automatically when power is restored, and when you turn it back on by hitting it's on button, it goes back to its default setting for sound type and volume.  I want a unit that comes on and off with a motion-activated switch near the toilet.

I contacted Dohm to see if their units would be more suitable.  They responded that their units come on the same way as the LectroFan - you have to hit the "on" button.

[MichiganMark]

I know what you're talking about with regards to the physical sound-proofing.  I built a home theater when this house was renovated and fully soundproofed that as you described using double-wall framing and sound-absorbing mineral wool.  It's wonderful.

The problem for the bathroom isn't as simple.  The size of the wall between the bathroom and bedroom is about 35 square feet.  Seventeen square feet of that is a hollow-core door, and I figure that about 3 square feet inside the wall is taken up by studs and the header over the door.  I think I'll start by installing a solid door. 

If needed, I can also drill some holes to shoot cellulose insulation into the 15 square feet of wall cavity, but I'm not sure that will help much because the relative size of the "treated" area is so small.

[eutectique]

urine hitting the toilet when I'm standing up while urinating and farting

In some cultures men urinate sitting down.

A sound-masking option could be an Otohime device.

[MichiganMark]

The recommendation to get a Toto Otohime is the winner!  Although it isn't hard-wired, and won't come on automatically, it was designed specifically for what I hope to achieve. 

The interesting thing is that otohimes are only available in Japan and they're covered in instructions in Japanese.  I've decided not to go to Japan to get a unit, but was able to buy one on eBay.

Thanks to all who helped with my quest.  Thanks also for the other humorous suggestions I could quickly expunge. 

Please don't stop posting! 

[reboots]

How about a fountain which creates competing sounds, rather than masking noise?

https://www.pyleaudio.com/sku/SLTWF85LED/

[eutectique]

The recommendation to get a Toto Otohime is the winner!

My pleasure

Please don't stop posting!

[Gyro]

In some cultures men urinate sitting down.

In men of a certain age, it also frees up both hands for the newspaper whilst waiting for the flow to commence. 

[themadhippy]

In men of a certain age, it also frees up both hands for the newspaper whilst waiting for the flow to commence.

who says us men cant multitask

[sparkydog]

Because I'm not afraid to use the common words for the sounds I'm trying to mask:  urine hitting the toilet when I'm standing up while urinating and farting.

One of the sounds you're trying to mask is probably similar to this.

Well, you could just "double down" and play the above or something similar. Of course, this may be counterproductive.

You can try to mask that with pink/brown noise. (Use in a second tab to play around with what that might sound like!) Frankly, I wasn't impressed. This seems slightly less objectionable, but IMHO the most pleasing results come from trying to harmonize with the running-water sounds rather than simply drown them out. To that end, I came up with this (which includes running-water noise; I'd keep that because, even though it "adds" the very noise you're trying to hide, having those sounds always present should make the actual noises you're trying to disguise less noticeable).

Unfortunately, the... other problem noise is, well, more of a problem. Because it's subject to much more variability in terms of volume, pitch and duration, it's hard to blend it with something else. You potentially need a fair bit of raw volume if you're going to effectively mask it, and the sorts of sounds that will do the job are much less pleasing than the semi-pastoral sounds from my suggestion for dealing with the first sort of noise.

[MichiganMark]

You still get a printed newspaper?!

[antenna]

urine hitting the toilet when I'm standing up while urinating and farting

In some cultures men urinate sitting down.

A sound-masking option could be an Otohime device.

Not to go off topic, but I clicked the link because, for some reason, I was curious enough to and I was shocked by the responses to that thread.  I had no idea it was that common for guys to sit down to pee lol.  I always stood, but with my excellent aim and billiards skills, I always shoot for the dry part above the water where the ceramic is at a steep angle so any droplets did a bank shot into the water.  Plus, at that angle, the surface tension helps minimize spatter anyhow.  Never had a problem with piss getting where it shouldn't that way.  However, having a few German friends and reading that, the expectation to sit is really going to mess with my head now.

[5U4GB]

while urinating and farting

I think you need to fit the sounds to the activity.  My suggestion:

while urinating

Handel's Water Music.

farting

1812 Overture (finale).

[themadhippy]

I think you need to fit the sounds to the activity.  My suggestion:

Quote

    while urinating

farting

[NiHaoMike]

urine hitting the toilet when I'm standing up while urinating

Aim a little off to the side, not only will it be a lot quieter but it also cuts down on splashing.

[Teledog]

I'd suggest an audio output of "Brown Noise";
https://youtu.be/RqzGzwTY-6w
 

[5U4GB]

You still get a printed newspaper?!

Sure, you can use it twice in the bathroom, once before, once after.

[EPAIII]

Well, I'm a guy and I sit all the time. Things stay cleaner that way.

As for the solid core door, it may help, but if you are going to go to the trouble of replacing it, I would look for one that is sound rated. They aren't cheap, but they beat the heck out of a solid core one for stopping the transmission of sound.

Other ways of decreasing the sound are sound absorbing panels in the room and real, not DIY home supply store, acoustic ceiling tiles. The holes in the DIY ceiling tiles may look neat, but when you check the acoustic ratings you find they do almost nothing. There are professional materials that actually work.

Likewise for fiberglass or other common insulation materials. They are for heat, not sound. A double stud wall is the first thing that works. Then some real sound absorbing material between those studs.

Some equipment you may want to look at. None seem to have any Start buttons but you will need to add amplifier and speakers (or amplified speakers):

https://www.markertek.com/product/st-ng1/rdl-st-ng1-white-and-pink-noise-generator?gad_source=5&gclid=EAIaIQobChMIo66L2onThQMV2DbUAR0SdQD2EAQYAyABEgIAs_D_BwE

https://rdlweb.s3.us-west-1.amazonaws.com/downloads/datasheets/st-ng1.pdf

https://www.sweetwater.com/c1200--Eurorack_Modules?highlight=Behr25001016&utm_source=google&utm_medium=organicpla&seoslug=behringer-1016-dual-noise-random-voltage-generator-eurorack-module&catrollup=498/1199/1200&mrkgadid=&mrkgcl=28&mrkgen=gpla&mrkgbflag=1&mrkgcat=drums&percussion&acctid=21700000001645388&dskeywordid=&lid=58700008695591288&dsproductgroupid=&product_id=Behr25001016&prodctry=US&prodlang=en&channel=online&storeid=&device=c&network=x&matchtype=&adpos=largenumber&locationid=9027887&creative=&targetid=&campaignid=21161059808&awsearchcpc=&gad_source=5&gclid=EAIaIQobChMIo66L2onThQMV2DbUAR0SdQD2EAQYBCABEgKYGvD_BwE&gclsrc=aw.ds

I had many more hits when I simply searched for "pink noise generator".

[BILLPOD]

In some cultures men urinate sitting down.

In men of a certain age, it also frees up both hands for the newspaper whilst waiting for the flow to commence. 

My prostrate also prompts the use of sitting, but also: "Drops of urine can splash up to 36 inches from the toilet, landing on a wall, mirror, or, god forbid, even your toothbrush."

[donlisms]

I confess I haven't read all of the postings; some I've only skimmed.  You guys are funny!  Well... some of you.

A couple things came to mind, perhaps going over old ground. Or things everybody already knows. (Sorry.)

The original objection to "white" noise was because the energy is distributed linearly, while our perception of sound is logarithmic.  So there's the same energy from 100 to 200 Hz, and from 1000 to 1100, and 1100 to 1200, and so on.

Our ears hear the bit from 100 to 200, and compare it to the bit between 1000 and 2000, which is one white slice compared to ten.  The high frequency chunk wins.  By a lot.

So pink noise is equal energy in the 100 to 200 and the 1000 to 2000 bands.  Nicely balanced for us humans and many of our sounds.  (Including music, the prototype of all that is wonderful.)

I've heard of brown noise, but reject the premise. I don't think it applies here, anyway. Pink noise has an appropriate rumble.

If the attenuation between the source and the destination is 20dB, which it very well could be, the actual power difference is a factor if 100.  So 1 watt at the destination end is equivalent to 100 watts at the source end.  Something to think about.

The amount of sound leaking through a  door versus through the little gap around the door can also be a little surprising.  You will find most of it is through that little gap, not the broad expanse of the panel.

Were it me, then, my first guess, my current thinking, would be in line with some of the others:

- some experimentation will be required.

- Insulate the gap around the door and see what that gets me.

- Mask the sound at the destination end rather than creating a potentially uncomfortable experience at the source.  Remember... the sound intensity for the listener would be the same in either case.

- Use a modified pink noise.  We certainly won't need response down to sub bass; rolling off the low frequencies could be as simple as using a less-than-stellar speaker. "Low enough" is all we're after. The highs will take care of themselves.

- Consider (seriously consider) just leaving it on, rather than trying to synchronize with the main event. (Those of us with tinnitus just leave it in always.)  one benefit is that other annoying noises get masked, too.  You could... try it, even if it seems kinda "nnnnnnyeh" at first thought. 

- If not continuous, the problem becomes remote switching or automation or something.  And soft-start - a sudden "on" of masking sound, no matter how it's done, will be a distracting disturbance in itself.  As will "off."  So volume ramping might increase the quality of the result, in addition to contributing to our primary goal: making life more complicated. 

I do love the basic problem. I've mixed live sound my whole life, and decisions about whether two sounds should be blended and making something truly merged, or keeping them separate and clearly distinguishable, is fundamental to the mix.  And the applications of the principles are everywhere... neighbors in apartments, trying to get work done, and so on.

[CarlosGarcia]

amplify, rotate phase 180 degrees and add

[Smokey]

Am I really the first one to say this???   Never Constipated Again!!

https://en.wikipedia.org/wiki/Brown_note

"The brown note, also sometimes called the brown frequency or brown noise, is a hypothetical infrasonic frequency capable of causing fecal incontinence by creating acoustic resonance in the human bowel."

(.... yes I know it's not a real thing ...)

[vk6zgo]

You still get a printed newspaper?!

You can't wipe your backside with an iPad in an emergency!

[Smokey]

You still get a printed newspaper?!

You can't wipe your backside with an iPad in an emergency!

.... challenge accepted!

[themadhippy]

.... challenge accepted!

cant do a worse job than the tracing toilet paper we had at school