[医] 失音[症]的; 无音的

[ adj ]
being without sound through injury or illness and thus incapable of all but whispered speech
<adj.all>

Aphonic \A*phon"ic\, Aphonous \Aph"o*nous\, a.
Without voice; voiceless; nonvocal; incapable of all but
whispered speech.
[1913 Webster + WordNet 1.5]