Electronic Active Noise Cancellation

[drawoh]

I am being asked about this. We are building a workstation in our factory that will be noisy, perhaps around 110dB. We are installing sound insulation. The racket will kind of scatter around our plant. Apparently, we can install a speaker system that will monitor the noise and emit reverse sound waves to cancel everything.

Has anyone got experience with this stuff? Will it work for people scattered around a fairly large work area?

--
JHG

 

[EdStainless]

There are companies that specialize in this work.
It works much better if the sound is from a concentrated area.
Often you have to build an enclosure in order to implement this.

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P.E. Metallurgy, consulting work welcomed

 

[GregLocock]

Yes I used to do ANC. Unless things have changed a lot then no it won't work over a broad area unless you can locate the speaker near the source, or a mic and speaker near each worker. It also needs a feedforward signal ideally to drive it. If the noise is not periodic then I think you've little chance of cancelling it effectively.

Interesting science project though.


Cheers

Greg Locock


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[3DDave]

AFAIK it won't work as it requires providing anti-phase and matching amplitude. This is tough enough with headphones when there it just a small hole leading into the ear to take care of.

Anti-echo sound absorption is the most effective approach short of building a box around the workstation and filling it all with concrete. I understand this may interfere with the work.

 

[MintJulep]

Yes, it can work in the right applications. It's most effective for steady-state periodic sources; e.g. rotating equipment, electrical hum, flow induced. Less so for sharp transients and impact noise.

The approach would be to cancel noise at the source.

A Google search for industrial active noise cancellation will turn up the leaders, including companies that can help you design a combination of passive and active noise control.

 

[rb1957]

We did a tonne of work on this on the DHC8. As 3DD says matching opposing waveforms. The co9mpany we worked with was Ultra (in the UK).

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.