Quote:
Originally Posted by Al Skierkiewicz
Mike,
I wish you had told me you were doing sound level measurements, I would have liked to participate in that. What were you using for instrumentation? Does your instrument average over time?
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Al,
1311 was taking data using a calibrated ExTech data logging sound level meter and a calibrated Sper Scientifice sound pen. Next year we plan on being there with a dosimeter.
some of the data is here, it is from Saturday afternoon and doesn't reflect the other days, I will post that later.:
http://www.kellrobotics.org/files/Sound_2008.pdf
Ed
Edit:
I just dug up some data taken at 2:15 to 2:30 in Curie - sound levels during matches were 88 to 95 dbA with peaks, during idle periods between matches 82 to 86 dbA, both cases A weighted with 1 second averaging intervals. Peaks for both periods at about 100 dbA.
What are my observations ? based on this data and the referenced report.
During Einstein - most excessive sound came from the crowd, rarely did we see an incident of the PA system with excessive level. That statement is tempered by the fact the fact that the crowd absorbs sound. This situation is comparable to a large football game. Even if you turned off the PA you would have to wear ear plugs.
During divisionals in Curie data appears that there is less crowd absorption, more PA, levels TOO HIGH. We don't have all the data that I'd like but it's a pretty solid bet that during prelims, and divisional finals the levels were way too high. Generally speaking at Atlanta and the regionals the PA is too hot during prelims and regional/divisional finals.
During Einstein I noticed something as we were recording data: It sound like a study in group dynamics behavior type stuff. After some speech or award presentation the crowd would begin clapping brightly then quickly taper to a long sustain clapp. The sustain always leveled at about 90 dbA, the threshold for discomfort. The level of the initial brightness was dependent on the thing being clapped for. The crowd was twice as loud for Dean Kamen as for everyone/everything else.
On the floor of the dome during divisional finals typical levels were 90dbA plus or minus 3, with constant peaking to 100 dbA. Even if levels were reduced floor officials and volunteers working all day should wear ear plugs.
At noon on Saturday our EHS people had a very long meeting with UL and they asked us to submit our report to UL and to FIRST. We will be doing that later this year and getting it to the right person. For the moment everyone, teams and FIRST, is taking a much needed break.