What's it like getting used to sudden severe hearing loss in one ear?
I’m going on this from personal experience (as I’ve got a hearing impairment which sometimes causes profound loss/tinnitus). Your entire person can be affected by a sudden loss of hearing - their actions are likely to be very different, e.g. favouring an ear which still has hearing, paying more attention to body/facial cues, even withdrawing from situations in which things may be “too noisy” as focusing with only one functioning ear can be immensely hard.
Depending on what age/stage a person is at, communication can be affected by this. If a person hasn’t already learned to speak, this definitely is affected by a hearing impairment.
Ears don’t just affect hearing though, quite often if there’s been a sudden dramatic loss in hearing, there’s something else going on inside the ear - whether this be infection, the hairs on the inside of the ear being damaged, the bones fusing. Often those with a hearing loss have issues with balance (as it’s controlled by the inner ear). Those with unilateral or bilateral hearing loss often suffer from headaches/tension headaches, and can get v tired or exhausted quicker - this comes from the effort of listening/lip reading/concentrating to make sure you pick up things around you. Problems with sleep are also common, particularly if you suffer from tinnitus (which a lot of people with hearing loss do, as the brain overcompensates for silence and “creates” noise).
If someone has lived for hearing loss for a while, the brain actually can begin to compensate for it, often by picking up on another sense.
But I can absolutely vouch that if it was to happen rapidly, or unexpectedly, disorientation would most likely be the first response. Then essentially the person would “re-learn” to hear with their other ear.