As an alternative to listening to unwanted background noise or uncomfortable silence, create white noise with the Raspberry Pi.

Using Raspbian (other distros may vary):
apt-get install sox

Create your shell script:
#!/bin/bash

len='7:00:00'
export AUDIODRIVER=alsa
export AUDIODEV=hw:0,0
play -t sl - synth $len pinknoise band -n 1200 200 tremolo 20 .1 < /dev/zero
(adapted from the unreasonable man)