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Sep 20, 2006

Noise and (American) footbll intersect: NFL rules on crowd noise (from the Seattle Times).

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Sep 18, 2006

Tom Gruber & Mark Brennan, working for the town of Cohasset MA, have written up a pretty good lay explanation of the train vibration analysis method used for the Greenbush line commuter rail project (check here if the previous link has expired). They also talk about the installation of the ballast mats (“vibration mats”) that will be used to mitigate excessive train vibration.

If you are a techie that wants a more rigorous treatment of the process, I’ll point you to Chapter 11 of the FTA noise & vibration guidance manual(PDF), chapter 5 of the Greenbush Final Environmental Impact Report, and my Noise-con 2005 paper describing an alternative method for testing the vibration response of the ground.

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Bob from Soundwave Research Labs makes an interesting comparison between the ongoing analog LP vs. digital CD debate and the Continuous Wave (CW)/AM radio debate at the turn of the 20th century.

His comparison strikes me as familiar: it’s not uncommon to see scientists, engineers and technical professionals who strongly prefer particular equipment or methods, even if obsolete. It’s one of the reasons why you see used and abused Brüel & Kjær equipment sell for thousands of dollars on eBay when a $500 Extech meter will suffice in many instances – many professionals grew up using B&K equipment, and they won’t consider anything else. Even I fall into this trap - for example I only use PCB ICP accelerometers, not because they’re the best for everything, but because I’m comfortable with the technology.

As a wise man once said: “Young minds, fresh ideas. Be tolerant!”

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Sep 07, 2006

Ars Technica writes about the new audio features that will be incorporated into Windows Vista. More info is available at this AVS forums thread.

Notable features include:

The room correction looks like it uses realtime FIR/IIR filtering which should help eliminate narrow frequency peaks and tips typical of most rooms. The bad news is that we apparently won’t be able to use our own microphone correction factors to calibrate non-flat mics. Therefore, your can only correct for room frequency response if you have a flat measurement microphone. Fortunately, suitable mics like the Beringer ECM8000 are available for less than $50. It also looks like you can use cheap, non-flat mics to perform time-delay corrections.

This is good stuff for us audio types. I’m usually a Mac guy, but I’m paying attention to VIsta now.

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