[robmiller]

Acoustics consultant here. Its too bad there's no mention of using a windscreen on the sound level meter, especially at 2 inch distance. It would make sense if the mesh performed best, while airflow was restricted nearly most if air rushing by the microphone element was contributing to the level measured, and not the noise of the fan itself.

[roberthahn]

I would have expected that you'd _want_ to factor in air noise because humans don't only hear fan noise in their computers. Or am I misunderstanding?

[MengerSponge]

You know how someone blowing in your ear makes more sound than when you blow in someone else's ear? The airflow itself can make sound from eddies and whatnot.

Most people don't put their ear next to a case fan to see if it's annoying or not. You experience its sound from several feet away, and the measurement should reflect that.

[ehnto]

I think they mean the excess noise of a volume of air moving past your ear, which is due to the turbulence created while air is passing over your ear and not the soundwaves being transmitted by said volume of air.

Practically speaking no you wouldn't want to factor the turbulence generated at the microphone because the user of the computer wouldn't be hearing that.

[joshuahutt]

What a cool and fascinating job you must have.

[robmiller]

Hey thanks. Yes, esoteric enough to keep it interesting day to day. I mostly work with architects and design engineers to coordinate quiet building systems and good interior acoustics--projects anywhere from K-12 to major performing arts centers to commercial offices, including some of your US offices...

On that point, I feel everyone's collective pain on the situation with open offices. I don't have the power to avoid them, so the best I can do is advocate for getting the signal-to-noise problem solved right.

[larrik]

They measured the intake side, though, so it was more of a vacuum effect. Would a windscreen still make a difference in that scenario?

[oliveshell]

I can’t think of why not. The velocity might be lower, but moving air is moving air.