![]() In other words to be compliant you have to meet not only the criteria for any directly relevant shorter time period but also all of the guidelines for any longer periods as well. NIOSH and OSHA don't address anything other the exposure over an 8 hour period and the charts presented are actually expressing how to relate shorter exposures during that 8 hour period to the allowable 8 hour 'dose'. repeated exposure by employees over multiple 8 hour periods. There are many misunderstandings regarding the noise component of OSHA and NIOSH and much of that seems to stem from the fact that OSHA and NIOSH both address long term noise exposure in the work place, i.e. Conversely, a system optimized for speech intelligibility may exhibit higher A-weighted SPL levels than might seem associated with the perceived loudness. Since A-weighting is actually based on human response at normal speech levels and not at concert levels, someone who understands SPL weighting can often play around with the frequency content to get greater perceived loudness for a given overall A-weighted SPL level. That's also the peak levels with the average levels being lower and I'm guessing those are more a "we were typically around 117dBC/104dBA during songs" than an actual TWA, LEQ or other statistically derived average. The 126dB is C-weighted SPL, a difference of about 25dB at 63Hz and 16dB at 125Hz from A-weighting, thus the 13dB to 18dB lower A-weighted levels. That may be an accurate application in some cases but some may not like that their performance being considered noise. Of course the irony in even trying to relate OSHA and NIOSH to concerts is that they address noise, which is unwanted or undesired sound. And the related information is often misunderstood and misapplied in trying to do so. ![]() The point is that while perhaps better than nothing, it is really difficult to directly apply OSHA or NIOSH to concerts or other events except in relation to the exposure of employees over an 8 hour time period. ![]() If I recall correctly that relates to a 85dBA 8 hour dose. For employees it is quite common to have source levels well over those allowed and to employ active and/or administrative measures to reduce their exposure, that is a bit more challenging to apply to an audience of non-employees that can come and go as they want and can use noise reduction measures or not as they please.Īlso often overlooked is that OSHA actually has a lower SPL level criteria that does not require active measures but that does entail having to establish a hearing monitoring program. That could mean reducing the source levels but it can also involve active measures such as hearing protection or administrative measures such as limiting the time one is exposed. OSHA and NIOSH also do not actually limit the source noise levels, only the resulting exposure. Thus that chart is not saying that a 105dBA TWA for 1 hour is acceptable but rather that it is allowable only if you also meet a 102dBA TWA for 1-1/2 hours, a 100dBA for 2 hours, 97dBA for a 3 hour period, 95dBA for 4 hours, 92dBA for 6 hours and a 90dBA TWA for an 8 hour period, all of which relate to the 90dBA, 8 hour noise exposure 'dose' that is allowed. **One EVA cabinet is the equivalent of two line-array elements.Click to expand.There are many misunderstandings regarding the noise component of OSHA and NIOSH and much of that seems to stem from the fact that OSHA and NIOSH both address long term noise exposure in the work place, i.e. Max array height can be extended if custom rigging frame is used. *Measurement when using an EV rigging kit. Uncompromising audio quality, ease of use and energy efficiency.Ĭomparsion of 120° models 120° model compsĢ-way, passive or bi-amp element with 12” wooferģ-way, bi-amp or tri-amp element with dual 8” woofersĢ-way, bi-amp or full-range element with 8” woofer Space, you can rely on EV line arrays to deliver an ideal combination of With options to suit the specific needs of your performance Mechanical performance, we talked to dozens of industry professionalsĪnd blended their real world insights with our decades of line array To achieve our goal of creating line arrays with the best acoustic and
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