|How Loud is That?||
I needed a testing apparatus for this project. I wanted something that would hold the hair dryer upright while I measured the decibel level from each side of the dryer, and from the rear.
Here is a picture of the tester I built. I drilled a 2 1/8" diameter hole in the top of an old shelf to hold the hair dryers and placed the shelf atop two overturned metal waste cans. I used an old pencil holder as an iPhone stand, and marked three positions: the same distance from the hole's center to the right, to the left and to the rear. (The markings are a bit off center to account for the microphone's location on the left side of the iPhone.)
Finally, I found the quietest place in my house to do the measuring: on top of my dining table. With the air conditioning/heating unit off, the ambient noise was only 33.5 dBs.