SPL metering, logging, alarm

Re: SPL metering, logging, alarm

Daniel Postilnik said:
We don't plan to use the official standards as hard rules for enforcement. I didn't even mention them in my original post. The idea is to be able to collect some data about sound levels currently being produced, compare that to the experience of being exposed to those levels in the studio for the allocated amount of time (for a customer, usually 45 minutes), reach a consensus among the decision makers at this company about what would be considered unhealthy, and then use the data to address customer complaints and recurring instructor violations.

I should mention that this is a company where everyone from the CEO, to the sound engineer, to the VP of operations, to the head of design, is expected to take classes on a regular basis to be in touch with what customers are experiencing. This is especially important when we want to be able to say to an instructor who is going deaf and taking others down with him/her: "Look, all these people of various ages and backgrounds who work for the company took your class and found it to be painfully loud, and we have data to indicate that you are above the guidelines recommended by several official bodies." Being able to monitor this data in realtime is also very handy, so we can identify the main offenders in the act.
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Maybe I'm misunderstanding but you seem to possibly be trying to address two related but different issues. Getting a consensus on what is deemed a discretionary 'appropriate' level seems a subjective determination by those involved and the discretionary aspect extends to both the acoustical descriptors used and the method by which they are measured. If the goal is simply to define some discretionary goal or limit then what that is and how it is measured is up to you and may or may not include referencing existing standards or other references. However, the moment you introduce references to hearing loss and any related standards you tend to introduce not only defined accepted practices that extend to the measurement tools and processes but may also introduce potential related liability issues.

So if you want to be able to tell an instructor that you think they are too loud then how that is defined and documented seems totally up to you. However, if you want to address hearing losss and especially any references to related standards then you probably want to be sure that what you are doing and how you are doing it are as compliant with those standards as possible. If the Owners are not wanting to commit to the latter then it may be best to completely avoid the topic of hearing loss.
 
Re: SPL metering, logging, alarm

Brad, you make a very good point. We can't refer to the standard unless our goal is to adhere to it.

Turns out that figuring out where to put the measurement device so it can't be seen is my biggest problem so far...
 
Re: SPL metering, logging, alarm

Daniel Postilnik said:
Bennett, I hope your reaction to those levels is not sarcastic. Our audio provider doesn't have an issue with building systems that produce such levels in a small enclosed space, just because a couple of deaf instructors require it.

Unfortunately subwoofers are the main culprit for acoustic penetrations, so they often get turned down first or even turned off at spaces that have particularly sensitive neighbors. This is NYC, and there are always neighbors...

Meanwhile, it actually occurred to me that an SPL meter that can report data wirelessly would be really great to have. Our company can almost definitely afford it.
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Hi Daniel, I have been very actively involved in this exact discussion and have extensive experience with your dilemma. As a matter of fact you and I are practically working on the same problem, except you do not know it yet lol. My tester records, logs and reports and I just recently completed a noise monitoring report for OSHA in a building next door to where you work.

Unfortunately an ideal product does not exist but if you can remote mount a reference mic in your studio and keep the tester in the office. The sad part is that the tester is rather expensive. Check this site out: Live Events: Comply with Sound Limits

My question to you is: How loud are your systems and which form of measurement are you using?
 
Re: SPL metering, logging, alarm

agreed, it sounds like you are describing what 10EaZy is/does. SPL logging, alarm, wireless or web viewing of display, dedicated hardware, etc. We (Rational Acoustics) are the US distributor for the product, you can check it out, and order it from the US site here: http://www.10eazy.us/

(disclaimer, I'm Chris at Rational Acoustics - we are the developers of Smaart, instructors of system awesomization, and now distributors of 10EaZy in the USA and Canada)
 
Re: SPL metering, logging, alarm

This question is related to what I originally started this thread for.

I used an SPL datalogger to collect SPL readings every second for 45 minutes. I want to be able to present this data in a meaningful way. What is the difference between an arithmetic average of the values and an Leq, which I understand to be a calculation of what the SPL level of a constant sound over the same period would be? I don't want to skip any important math, and if necessary, I would be amenable to plugging in some calculus formulas into excel to get what I need.

Just to be clear, the datalogger I used does NOT calculate Leq on its own.
 
Re: SPL metering, logging, alarm

I am not an expert when it comes to the math, but from what I understand - Leq is basically a FIFO average, over the a designated period (typically 15-60mins). An arithmetic average would be the mean value of all data collected. So I suppose an Leq of 45 mins and an arithmetic average of 45 mins would result in the same information. Please correct me if I am wrong.
 
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