deaf-aid

n small (usu electronic) device that helps a person to hear; hearing-aid 助听器.

deacon, deaconess, deactivate, dead, dead heat, dead man's handle, dead reckoning, dead weight, dead-beat, dead-pan, deaden, deadened, deadline, deadliness, deadlock, deadly, deadly nightshade, deadpan, deaf, deaf mute, deaf-and-dumb, deafen, deafening, deafeningly, deafness, deal, deal in, deal out, deal with, dealer, dealing, dealt, dean, deanery, dear, dearest, dearly, dearness, dearth, deary (also dearie),