Sound Masking

Projects General Guidance
1

Hi,

I am currently working on a concept project where I want to mask human speech in an area with Pink noise. And i request the help of you.
The area is a work / study place where you have 3 work areas where there is 4 computers, 2 and 2 opposite of each other.

Like "illustrated" in the picture below

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  • What i want to do is to use 3 sound sensors (one over each work area) to measure the average sound every 5 seconds and have 6 speakers (2 over each work area) output Pink noise.
  • The measurement has to be the average over 5 - 10 seconds, depending on some small testing etc.
  • If it is possible to filter out the measurement of the pink noise.
  • The output needs to have a max limit so the sounds doesn't get to much and starts to be to much.
  • I also want a control board where I can manually override the output.
  • At the end i would like to have a report every day of the sound level sent to my mail.

All this is just a concept and i would like to know if this is possible. What i would need to make this (As cheap as possible, but not so cheap it does not work properly)
If this is possible i also need someone to write this code for me. I would like to the union to own this code so there would be a small fee in it for the person who writes the code that will make this work (the fee will be discussed, and can come after the concept is proved to work)

If there is any questions or any suggestions to alterations i would take that with open hands. This is done by a student union for a study place so I would like to get this done as fast as I can.

Thank you!

2

All this is just a concept and i would like to know if this is possible.

Yes, if you place the speakers and microphones correctly, and use the right kind of (directional) mikes.

What is pink noise? Pink Floyd played through worn out speakers turned up too loud? What, exactly, is going to be generating the pink noise?

  • I also want a control board where I can manually override the output.

The output of what? The microphones? The speakers? The Arduino?

  • At the end i would like to have a report every day of the sound level sent to my mail.

That is going to be the hardest part. Perhaps you should just plan on checking a web site every day, instead.

What i would need to make this

Six Arduinos, some things to generate the pink noise, some good quality, directional microphones, ethernet shields, and some programming skills.

As cheap as possible, but not so cheap it does not work properly

It isn't going to be cheap at all.

i also need someone to write this code for me.

$100 an hour, until I am satisfied that the code works.

so there would be a small fee

There will be nothing small about the fee, except for the thickness of the credit card that is used to supply the payment.

the fee will be discussed, and can come after the concept is proved to work

Not bloody likely.

3

What is pink noise?

It's white noise (purely random wideband noise that sounds like "SSSSSSSSSSSS....") that's been low-pass filtered at 3dB per octave for a less harsh 'SHHHHH..." sound.

I think this is all possible, but it's not "easy" and I'm not sure the workers will even like it. It might be more practical to buy everybody a noise masking gizmo for their desk.

Or, maybe build some walls! ...If you have to pay someone to help you with your sound masking project, and you figure-in all of the costs it might actually be cheaper to build walls!

  • If it is possible to filter out the measurement of the pink noise.

It's possible to mostly filter it by subtraction (which can be done with an analog differential amplifier). You "simply" subtract the electrical pink noise signal from the total (amplified) signal from by the microphone. But, but you have to allow for the speed-of-sound delay between the sound generation and the pick-up by the microphone. And, there will be frequency response irregularities from the speaker & microphone and acoustic reflections and anomalies that will make the subtraction imperfect. And, with 6 speakers and 3 microphones there will be more than one delay to work with.

If this is possible i also need someone to write this code for me. I would like to the union to own this code so there would be a small fee in it for the person who writes the code that will make this work (the fee will be discussed, and can come after the concept is proved to work)

I'm with Paul on this one (except I'm not offering my services). I'd guess this is a 6-month project.... Maybe not full-time, but I don't see you getting it done much faster than that. That's probably something like 1/3rd hardware design, 1/3rd construction, and 1/3rd programming.

That means it has to be a labor of love by an amateur, or it's a major "product design" project with a big budget. And, $100 an hour is about right... A "small payment" isn't going to get anyone interested. The cost of hiring a programmer on a consulting/contracting basis is about the same hourly rate as a plumber or auto mechanic. And because the software specs are never carved in stone, these are almost never fixed-price contracts. There might be a "not to exceed" clause, but that doesn't guarantee the job will be completed to your satisfaction when the money runs out... It means the contract comes to an end and you can re-negotiate if you wish.