No, my mattress is foam. My guess for you is the pillow isolates noise around the phone so it's easier to hear and the added RF attenuation by bed/mattress mate

No, my mattress is foam. My guess for you is the pillow isolates noise around the phone so it's easier to hear and the added RF attenuation by bed/mattress material makes it send at higher txpower. See also: https://en.wikipedia.org/wiki/Microwave_auditory_effect https://en.wikipedia.org/wiki/Microwave_auditory_effect