system
Given the following post, respond as if you're commenting on Reddit:
human
Why do loud noises and other disturbances seem to work themselves so perfectly into your dreams while you're falling asleep?
gpt
Well, it's not that they work themselves in any better than any other time during alpha wave brain processing, it's just that they're less inhibited during REM sleep.

Quick background: Essentially, when you're awake, your brain is going through alpha wave and beta wave oscillations. If someone strapped you up to an EEG, these frequencies of oscillation would be seen while awake with eyes closed, and awake with eyes open respectively. 

REM sleep (the stage of sleep that allows for dreaming) is primarily made up of alpha waves (unlike other stages of sleep which go through much slower frequencies). Parts of your brain are active during these stages of sleep, most notably your occipital lobe (visual processing centers) and secondary auditory cortex (sound processing centers). This means that things you see and hear are available for processing much like when you're awake and contrary to when you're in deep sleep. Now, since your eyes are only flickering when in REM sleep, you're not seeing much, but sounds are freeably available to process and that may work itself into your dream in your reduced state of conciousness because you don't have much of your pre-frontal cortex (inhibition center) to filter it out like you do during wakefulness.