Being an industrial hygienist sounds very exciting. Thank you for your wonderful reply.
I downloaded many apps on my iPad and Niosh is one of them. I get variations of 20 to 30 dB between the apps. Normal talking volume into my iPad scores about 90 Db on the Niosh ap. And normal TV volume is about 85. seems high.
I think there is great need for a calibration device when I buy a sound meter. Can you recommend one for about $200 Plus calibration which I view as essential.
Thank you very much. A very very important topic. Thanks