One hear is worse. Audiometric testing can identify an asymmetric hearing loss. That is one ear is worse then the other. We see this often in hunters who use a shot gun. If it is not related to noise exposure, you need to see an ENT doctor for diagnosis.
Hearing loss. Asymmetrical hearing loss just means that one has bilateral loss of hearing one worse than the other. Testing is with audiometry.
One ear hears better. In asymmetrical hearing loss (hl), one ear hears much better than the other. A formal audiogram (a hearing test done in a soundproof room) is the best way to test for hl. The test will tell ents if you have a conductive loss (transmission of sound is blocked), a sensorineural loss (hearing nerve isn't working), or a mixed loss. Ents classically evaluate patients with asymmetric hl.