So I’ve become somewhat obssessed with sound level meter apps for the iPhone. After I bought dB from Faber Acoustical I was confounded by the usual complaints I encountered on sound level app comments pages – that it registers too high decibel levels. I mean, 77 decibels at a poetry reading, at a coffee shop, with a peak of 92 dB? Yes, the speaker’s voice was amplified, and partly, I was looking to find out how much that added to the ambience. I did a quick reference check with SPL
(Studio Six) and it read in the low 50s. Then the answer came to me, of course, it’s unweighted, so it’s picking up all those rumbling low frequencies as sound level pressure. Still, 20 dB is a lot! But how can I resist it when it puts out cute overlays like these.
Hard to explain at each one though that it is off by over 20 dB. I guess I’ll have to put together my own using a camera and SPL readings, unless I spring for Faber’s Signal Meter. A more detailed post to follow about the poetry reading and its ambience, including a couple more readings and snapshots. Look under Aural Postcards.