1) Any judge, at times 2) Attender 3) Audience member 4) Auditor 5) Beholder 6) Concert attendee, literally 7) Confession taker 8) Eavesdropper 9) Judge 10) Judge at work 11) Judge, often 12) Listener 13) Mediator, at times 14) Observer 15) One catching some waves 16) One that listens 17) One who listens Found on https://www.crosswordclues.com/clue/hearer