Adding background sounds

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Background Sounds - MRH Aug 2011






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Great Article, minor comments...

Dear MRH fans,

Rich has put together a great article here, and I totally agree that background sound can materially enhance the overall presentation of a layout, whether in a home environment or for a "touring layout".

However, a few comments come to mind

- "Obviously repetitive loops" are a commonly cited issue with layout sound. The need for such obviously _short_ loops is often a response to the kind of limited-recording-length digital playback devices offered by some Model RR companies. As Rich notes, the "user loading" functions of even cheap MP3 players and similar animals allow the Modeller to deploy _exactly_ the kind of sound their _ears_ tell them suits _their_ layout, while allowing "loops" which can measure in the _hours_ of duration.

FWIW, a reasonable quality MP3 file eats around 1MegaByte per minute of Stereo audio. Therefore, even a "tiny" cheapo 1Gb MP3 players can handle up to 1000 minutes of audio, or over 16hours of audio!

- Overall volume (referred to by Pro Audio bods as "Gain") is indeed a key element to deploying Layout Sound.

It is entirely possible to recreate, for example, a HO scale warehouse dance party,
providing a tangible "doof doof" bass rumble to a viewer leaning into the model scene,

while _not_ exceeding 60dB SPL
(for the non Audio bods, that's quieter than you and I having a close serious conversation between ourselves in a quiet room), 

and being _inaudible_ (or at least not peaking above "conscious level") for a person standing 2 paces away.

- I have to note that a "USB compatible" 5VDC supply is not hard to make, and for those modellers who dislike electronics at the best of times, there are some plug-n-play 5VDC USB-plug-type supplies available from RadioShack, Maplin, and Jaycar. I am unsure why Rich reccomends against USB-powered units, if you intend to deploy the LayoutSound systems on anything other than an occasional basis, replacing AAA batteries is going to get old. (If you only run the sound occasionally, you're actually _more_ likely to _not_ check the batteries on any regular schedule, and therefore discover that they are dead or have leaked within the MP3 player right when you _need_ them...)

Furthur, it can be a good move if you can find MP3 players that _automatically_start_playing_ when power is applied. This makes it easy to run a additional "layout sound power buss" which can be turned on or off with a single switch.

- Side-Note: When choosing an MP3 player for Layout Sound missions, if at all possible, perform the following test _before_ buying.

* turn it on,
* start a file/sound playing
* set the volume to a given level
(It doesn't particularly matter what level you choose for the purposes of the test, but probably best not to choose "full volume")
* turn the MP3 player OFF
* then turn it back ON again

The key point is, when you re-turned-ON the player, did it "remember" the volume setting you set earlier?
If it _did_, then you can buy and deploy them under your layout, confident that when you "power up" the players everything will be as you intended.

If not, every time you power up the players, you'll be resetting the volume to an appropriate level, which may wear thin after a while.

- Rich is correct, both PCs and MACs both come with applications within their Operating Systems which will allow basic Audio Editing to be performed. However, if you are reading this post, you are also likely online. This means that you are only moments away from downoading a _FREE_ dedicated Audio Editing app, such as Audacity

Such apps are more powerful than Sound Recorder or Movie Maker (Win) and iMovie (MAC), and just as easy to use. (If you can drag and drop a sound file into any of the above, push a volume fader, and export a MP3, you can do it in Audacity, with better audio and exporter algorithms and more accurate control for a better audible result).

- Downloadable sounds from online are definitely a quick way to get _something_ up and running. However, be fully prepared that the downloadable sounds may

* be low (digital audio) resolution (to save space online, unfortunately to the detriment of the audio quality itself)

* have unwanted background sounds (a better-equipped Audio Editor such as Audacity will shine over MovieMaker and iMovie under such conditions... :-) ).

* have unwanted/in-appropriate "ambinece" (think of a church bell which is physically modeled right at the edge of the layout, and thus up-close-and-personal to the viewer/listener, but the sound has an audible "reverb and delay" ambience which suggests that it's much furthur from the listener)

* oh, and just because it's online does _not_ mean it's free for the taking. Suggest starting at a bona-fide _freesound_ site, such as "the FreeSound Project"

- Agree that "periods of quiet" help avoid ear fatigue in the layout viewers. However, make sure to fade the Heads (starts) and Tails (Ends) of each effect. A "sudden start" of audio is often just as jarring as a "constant rumble" (NB that in some environments a "constant rumble" at very low volume, such as in a city-scape, may be entirely appropriate! :-) ).

- If at all possible, start and edit using WAV file format audio. This will give you _some_ fighting chance of producing a reasonable-sounding result. As above, audio posted online has filesize as it's _first_ priority,
and audio results second. Anything you can do to improve this situation, or at least "stop the degradation", has to be a good thing.

(As many Pro Audio bods have said for many years:
"you can make a good signal go bad,
but you can't make a bad (read:low resolution or degraded) sound come good...")

- Here's something that wasn't mentioned. If you edit your sounds on your PC, connected to your PC speakers, then when you play the end result back thru the speakers mounted in/on/around the layout,
the change in speakers will have a definite effect on the sound.

What to do?

Well, Pro Audio bods can only _wish_ that they could mix their audio (TV shows, pop songs, whatever) on the actual speaker system the End User will be listening to it on. Indeed, they spend deliberately spend significant time/effort/$$ setting up at least 1 set of "basic bookshelf speakers" (as opposed to High Fidelity ultra $$$ Studio Monitor speakers), in an attempt to "hear what it will sound like" on a "domestic home speaker system".

Hey, assuming you're using a laptop (or a machine dedicated to "model railroading" missions, as IIRC Joe F's surveys indicate a significant percentage of MRH readers have at their disposal),

why not

* download the "Raw sound files" you intend to create (kitbash?) onto the machine
* get your "basic edit" happening
* get the speakers at least "roughed in place" on the layout
* plug the Editing PC connected directly to the now-installed Layout Speakers
* and then complete the edit, _confident_ that the sound you are hearing during the edit is actually what you'll hear once it's all edited and deployed "for real"???

- As above, MP3 files eat around 1MegaByte / min of stereo audio. In comparison to CD-spec WAV files at 10MegaBytes / min of stereo audio, so absolutely yes, MP3s are indeed smaller. However, actually _creating_ usable MP3 files without compressing the life out of your carefully-crafted soundtrack is not quite as simple as just hitting "Save As MP3". If at all possible, suggest choosing 320kbps Constant bitrate and Normal Stereo compression in order to avoid un-necessary additional degradation.

I would also suggest considering:

* saving the _Project_ somewhere on your system, so you can come back and re-edit the soundtrack without having to re-build it from scratch in the future.

* once you're happy with your soundtrack, save a copy as a CD-spec (44.1Khz 16bit or better) WAV file, for _archive_ purposes. This means that, if in the future you change the playback hardware, and need to compress the soundtrack into some _other_ audio format, you will be starting with a _decent_resolution_ version of the final edited file. This is far better than re-compressing the already-compressed MP3 file version, and simply adding digital processing degradation to the process...

Again, Rich, Love the article!

Hope this helps...

Happy Modelling,
Aim to Improve,
Prof Klyzlr


caboose14's picture

Very clever!

The use of inexpensive MP3 players.........very clever! I always enjoy seeing Rick's layout and the sound effects are a nice added touch to the visiual images. Thanks for sharing this trick Rick.

Kevin Klettke CEO, Washington Northern Railroad

rtw3rd's picture

Thank you, Professor!

Prof Klyzlr,

Thank you for your thoughtful comments and suggestions on my article.  That's one of the things that I love about MRH is that I learn as much from comments on articles that I write as reading many of the articles!

I wanted to add some comments also since you raised some questions in your posting:

"I am unsure why Rich recommends against USB-powered units"  I made the recommendation as I thought it would be best to power the MP3 players other than though a USB input.  I didn't put it in the article, but a made a "battery eliminator" for the AAA battery using a piece of wooden dowel rod and copper wire that powers the MP3 players from a plug in transformer.

"Further, it can be a good move if you can find MP3 players that _automatically_start_playing_ when power is applied. This makes it easy to run a additional "layout sound power buss" which can be turned on or off with a single switch."  Excellent point, as I have to start up my MP3 players manually each time because they have "soft start" by pushing and holding the power unit unit they power up.

I also use Audacity and highly recommend the program.

"oh, and just because it's online does _not_ mean it's free for the taking. Suggest starting at a bona-fide _freesound_ site, such as "the FreeSound Project""  Great point!  Always make sure that no copyright laws are broken!

Thank you also for your detailed in-depth ideas on "taking it to the next level".




rtw3rd's picture

Thanks, Kevin


If I'm anything, I'm CHEAP, so I'm always looking for ways to save money.  I'm glad that you found the article helpful.



For a dam, our club uses an old AM/FM radio set between stations. The hiss can simulate water flowing over a dam.

Not sound, but we set a FM radio on a station and plug in a 1.5 volt, 1.2mm light bulb to the phone jack and set the volume to flash the light. Arc welding in a factory building. We color the bulb some with a blue highlighter marker.

We found out we can not do that with an AM radio as the NCE DCC Power Pro generates RF in the AM frequency band and we get a continues light.

Small AM/FM radios can be found at tag sales. A simple LM317 voltage regulator with a couple resistors and capacitors and we replace the battery. We tie the regulators to the 12 volt DC buss wires used for layout lighting.


Rio Grande Dan's picture

Great Article Rich

After reading your article I came here to comment when first Saw Prof Klyzir comment _

Great Article, minor comments.

All I can say is I wonder what he would have said had he made a Major Comment.cheeky

Now for my Minor Comment! Very good article and for me back ground sound would be nature sounds in the mountains and wooded areas, Bird and animal sounds as well as farm animals in the field and farm areas. I can see industrial sounds portraying a saw mill or chain saws near a logging area and water fall and river water sounds near streams and a water wheels at a mill. I don't think putting a band playing in a barn or a warehouse with a thump thump would be what I would choose for back ground noises on a model railroad but to each their own.

Again, Great article Rich I gave it 5 stars and feel it was very well thought out and well worth the read.


Rio Grande Dan

Greyhart's picture

To Auto Start or Not To Auto Start

Prof Klyzlr said:

Furthur, it can be a good move if you can find MP3 players that _automatically_start_playing_ when power is applied. This makes it easy to run a additional "layout sound power buss" which can be turned on or off with a single switch.

Am I missing something? It seems to me that speaker wire is relatively cheap. Why not place the speakers where you want them on the layout, then run the speaker wire to somewhere convenient for placing the MP3 players? You could even solder a jack onto the wires so that you can plug the speakers into the MP3 player, that way when you have to replace the player, you simply unplug it from the speakers.

 At the least, you could place players around the layout at the front of the bench work, where they can easily be reached.


 Ken Biles

My First Model Railroad





rtw3rd's picture

Auto Start


You make a good point, and that is exactly the way I've got my MP3 players connected.  They "dangle" out of sight under the fascia curtain.  To start them up I simply reach under and push / hold the power button until they start.  It only takes a few seconds and is no big deal.  Thanks!


Barry Oz's picture

Sound Ideas


Thanks again for sharing your ideas used on the Richlawn MRR.

The relative simplicity of sound effects in your demo video has me thinking how to display various aspects when the BARRY OZ RWY becomes a reality. Construction of the framework has begun and when time permits will post a blog on my progress


Barry Oz Railway



rtw3rd's picture

Sound Ideas


I'm glad that you enjoyed the Background Sound article and hope that you can use some of the ideas on your layout.  I look forward to seeing your progress on your blog.


carnellm's picture

Great article

Very cool article!  Gave me lots to think about. And since I am a tech geek, I even have some spare MP3 players around and extra speakers. I also see them for dirt cheap all the time at GoodWill and yard sales.

While browsing around for sound files I came across this site - 55 Great Websites to Download Free Sound Effects. I plan on assembling a bunch of long loops and when done will post them to my site. Would be great if others who take the time to do this might post theirs as well.

Oh, and I second the recommendation for Audacity! Excellent software, cross platform, and free.

Michael Carnell - Charleston, SC
My Model Trains

Charleston Rail

rtw3rd's picture

Thanks, Michael!


I'm glad that you found the article helpful.  Since the small memory MP3 players (less than 1gig) are "yesterday's news" you can get them dirt cheap; however, they probably won't be around forever as the value goes down they will probably end up in the trash.  I never thought about Goodwill and alike as a source - thanks for the idea!

And, a great idea about posting sound files for others to use.  I'll have to see if I can post some to my site.


Barnz's picture

re: doubling your sound investment

Hi Rick - great article on using MP3 players for background sound!


I am in the process of building my sound files right now.

Being as cheap as I am I thought I would use the left channel for one set of sounds and the right for another.

That way, I can 'sound-up' two areas of the layout for the price of one MP3 player.





rtw3rd's picture

2X your sound investment


Using each channel with a separate sound file is a great idea and, as you say doubles your investment!  Thanks for the idea!


Nick Muff does "layout sound"?

Dear Layout Sound fans,

Was just watching the Nick Muff interview here

and at the 15:40 point he shows a very simple "audio animation" of a hobo camp, using a Hallmark card as the Audio Source, and a cheap PC speaker rig to give it the required oomph...


Happy Modelling,
Aim to Improve,
Prof Klyzlr

About sounds

In real life sounds are usually perceived just close to the source, like the hobo camp mentioned above. As scale applies to distance the camp should not be heard from a few inches away, a diesel loco engine from a couple feet , a flying jet would cover everything else and so on. Sound could be used to highlight something close to the edge of the layout (like "hey buddy, look at this" "holy smokes, it has SOUND too!"), otherwise it would probably create unwanted background noise if overdone. My 2 cents.


Long life to Linux The Great!

rtw3rd's picture

Card trick


I saw that use of the sound greeting card and that's a good idea!


rtw3rd's picture

About sound (levels)

You are correct - volume is very important as the sound should not overpower the listener.  Background sounds should be just that - background.


bear creek's picture

(un)sound levels...

I live about 10 miles from the nearest railroad. Yet sometimes I can still hear the diesels rumbling and horns blowing for grade crossings -- sometimes, not all the time. And it doesn't sound like I'm next to the track, it has to be pretty darn quiet for this to happen.


 Contributing Editor, Model Railroad Hobbyist magazine

Greyhart's picture

Sound and Distance

I live about 10 miles from the nearest railroad. Yet sometimes I can still hear the diesels rumbling and horns blowing for grade crossings -- sometimes, not all the time. And it doesn't sound like I'm next to the track, it has to be pretty darn quiet for this to happen.

I live about 3 miles from the nearest tracks, and I can hear the horn clearly all day as the trains come to grade crossings. There are about four crossings. I'm not sure, but I wonder if there is a setting to soften the horn at night, because there doesn't seem to be much difference in the volume at night. If I'm outside on a quiet night, I can hear the prime mover also.

What you can hear is dependent on the volume of the source, the atmospherics, and what is between you and the source.

All that being said, I agree that background sound, when done right, should give more an impression of the area, not an announcement. If you're running a train, you probably shouldn't hear the sounds, but they would register, so that you would know there was a difference with sound, but probably not be able to put your finger on what it was.



 Ken Biles

My First Model Railroad





rtw3rd's picture

Sound & Distance


Well said!  I'm about 15 miles from the nearest railroad track (Gainesville, Ga) and can only hear train horns on a very still night - what a beautiful sound!


hoffertg's picture

Rexall Building

Great article!! Something I would like to incorporate. Unrelated question, the Rexall drug store. Whom was the manufacturer of the kit?? The building has some interesting details that relate to a buildings in my town.

rtw3rd's picture

Rexall Building


I'm glad that you enjoyed the article.  Here's the info on the structure:


The Rexall building is the last one on the right.


hoffertg's picture

Paint formulation for Rexall Building

I realize that this question is unrelated to your article, but can you give me the paint formulation that you used on the Rexall drugstore building on Merchants Row 1. Was it acrylic or enamel? and what paints did you use to obtain that particular shade of brick color?


Thanks again.

rtw3rd's picture

Paint formulation for Rexall Building

I'm glad to answer any questions about my railroad!  Unfortunately I can't provide the exact formulation for the colors on the Rexall store trim as it was a custom mix of acrylic paint (Apple Barrel).  I just mixed a color I liked.  For the brick colors I use spay primer (red & brown) from different manufactures.


ekul24's picture

Battery eliminator

I didn't put it in the article, but a made a "battery eliminator" for the AAA battery using a piece of wooden dowel rod and copper wire that powers the MP3 players from a plug in transformer.

Hi Rick,

Really great idea and article! I wondered if you would mind sharing more about your battery eliminator? I've managed to a good handful of similar mp3 player units and am trying to figure out how to wire a bunch of them up to a spare transformer, but have become a bit stuck. 



rtw3rd's picture

Luke, I'll see what I can do.


I'm glad that you enjoyed the background sound article and found it helpful.  I'll get some pictures together and do a little "how to" on the process to assemble the battery eliminator.  Just to confirm, this only works for MP3 players that use either AA or AAA batteries.  It's not for the players that have an internal rechargeable battery that is recharged by a USB port on a computer.


ekul24's picture

Thanks Rick!

Yes to confirm I have AAA powered units, (they look almost identical to the ones in your article). I've got plans to use them for background sound tracks and also use some for on demand sound effects like bells and whistles and the like, mounting them on or behind the fascia in effect using them as sound modules. 

I really appreciate your time, thanks again.


"trigger on demand" sound modules for LayoutSound missions

Dear Luke,

You may find that MP3 players don't work soo well as "trigger on demand" units. Put simply, they aren't designed to work like that. (No explicit/predictable "trigger Switch #1 = plays AAA.WAV, trigger Switch #2 = plays BBB.WAV" behaviour). 

There are numerous Model RR "sound modules" available "RTR", based on the digital-notetaker/Hallmark-greeting-card ISD chips, which _are_ designed/intended as one-shot "trigger on demand" systems.

However, their actually audio capabilities aren't much to write home about, (8Khz 8bit, Ugh!), and "loading your own sounds" is not easy. (A talk to George Solvey at ITTC can get you a "custom loaded" ISD-based sound module, if you ask nicely, and provide a suitable sound file).

However, if you want a "built for Model RR" sound module, with CD-spec (44.1Khz 16bit WAV) playback, full range of "trigger on demand" playback configuration, and SD/MicroSD card audio storage (IE many hours of user-loadable sound capable), then you might be well advised to check out the DreamPlayer family from Pricom...
(DreamPlayer "Classic", watch this space for something New soon!)
(the baby of the new DreamPlayer family)

The MP3 players will work great as "ambience" soundtrack players, and allow easily user-loading of homebrew/"scratchbuilt" layout soundtracks (INC panning and positioning of various "noisemakers" within the speaker soundfield, adding acoustic and environmental ambiences, etc)

but for realtime "trigger on demand" duties, I'd suggest you'll likely end up looking elsewhere...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

PS Just to be clear, I'm not involved with Pricom in any way, 
except as a Very Satisfied customer, and fan of their products.

PPS If you're interested in discussing _Layout_ sound,
consider checking in with the "LayoutSound" yahoogroup

ekul24's picture

Thanks for that info Prof

I know what you mean about triggering each of the individual sound effects. However I should have disclosed that I have a huge stack of these 1GB players and enough speakers to boot (supplier wanted rid of them at a bulk price really really cheap!). I have more than enough players/speakers so I intend to run one sound effect per unit. I have a small layout and plans for about 6 background sound units and 8 on demand sounds so 14 units in all plus some spares.

My testing thus far with batteries has been very pleasing but you can imagine that with a large number of players that Rick’s battery eliminator sounds pretty intriguing!

On these particular units pushing the play button plays the one and only sound file immediately, and the unit can also be configured to remember volume settings and the auto standby can also be disabled making them a play on demand unit, they also start up automatically when power is applied.  

With these units configured in such a way I don’t see a material difference to a commercial triggerable single sound module, unless of course I’m still to discover the other drawbacks. What do you think?

That pricom player looks like pretty good unit, so if the mp3 players don’t work out I’ll look into some of those. Presently my major limitation is $$$, I found these players by chance and at an extremely good price. If they fail to work acceptably for on-demand sound at least I’ll have background sound and I can look for something else for on-demand stuff.

Thanks too for the layout sound group link, it looks like there is some great information there. I’ll have to spend some of my forum hours over there having a look around.

Cheers for the help!

Luke smiley

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