AFMG Network Forum

hasia · Member

When should I consider Signal Masking in the calculation option? What the difference between Noise and Signal Masking for STIPA calculation?

Thanks.

Lindsay S · Member

Noise is the ambient level of the space that you are evaluating. This is crucial; without an accurate level your results will probably be completely meaningless. In other words, the higher the ambient noise level of a space is, the lower you STI rating. You should enter in the frequency characteristics of the ambient noise level if you have it, otherwise enter the overall anticipated or measured level.

Noise masking has to do with how the ear processes sound in a non-linear fashion. The short answer is that this is typically mainly significant for very high sound levels. If you search for Steeneken, you can find more information on this.

I always leave both of these checked. One of my annoyances is that I haven't found a way to make these set as "on" by default. If you are looking at the STI mapping and go to preference to turn these on, it will recalculate the map each time you check one of the boxes which can take minutes. When I'm evaluating STIPA I set these in preferences while I'm still looking at coverage patterns.

Lindsay Smith
Seattle

hasia · Member

Hi Lindasay,
Thank you very much for your reply.

I am working for PA system in large station glass box. It assumes 80dbA ambient level, ie approximately 75db/octave. SPL goes around 85-90 dba, which is subject to continuous level dependent auditory masking as per IEC60268-16. Doesn't EASE consider that by default?
I thought this Sound_masking, as-
https://en.wikipedia.org/wiki/Sound_masking
Do you have any insight about that!!!
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I am also confused about calculation RT. I used AURA. According to the tutorial, EDT, T10, T20, T30 in AURA represents RT. But for my project, they vary by upto 1-2 Sec. Which value should I consider as RT?

Thanks again.