Hopefully someone with access to the full article can answer these: According to the abstract, they tested phones on and muted or off. A phone that is powered

Hopefully someone with access to the full article can answer these: According to the abstract, they tested phones on and muted or off. A phone that is powered on (but not on a call) shouldn't be expected to use the radio much. Is it the case that the only difference was the power being on or off? Any explanation given for why they compared powered-on vs. powered-off instead of, e.g., airplane vs. non-airplane mode? Next, every phone I've seen with a mute feature mutes the audio FROM your phone, not TO your phone. Some phones also make a hiss even when they're supposed to be silent. Electronics can themselves hum, sometimes at a high enough frequency that only some people can hear it. Is it possible that there was an auditory difference between the two test conditions? Cell phones that are off vs. on look different (e.g., screen) and feel different (e.g., heat generation). How was blinding maintained? Speaking of that, how did they control for one being warmer than the other? Abstract says it was placed on the ear, so assumably the subject could feel that. When they say that phones were placed on the left and right ears, what do they mean? Hopefully they used a random ear for the "on" phone.