WordNet (r) 3.0 (2006):

unhearing
    adj 1: totally deaf; unable to hear anything [syn: profoundly
           deaf, stone-deaf, deaf as a post, unhearing]

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "unhearing":
   a stranger to, asleep, blind to, caught napping, dead to, deaf,
   deaf and dumb, deaf to, deaf-eared, deaf-mute, deafened,
   dull-eared, earless, hard of hearing, impercipient,
   in ignorance of, incognizant, insensible, insensible to, mindless,
   napping, nonconceiving, not with it, out of it, stone-deaf,
   stunned, surd, thick of hearing, tone-deaf, unaware, unaware of,
   unconscious, unconscious of, uninsightful, unknowing, unmindful,
   unmindful of, unperceiving, unprehensive, unrealizing, unseeing,
   unsuspecting, unwitting, witless, word-deaf