Question

incapable of being heard ( one word substitution)

Answer 1

Deaf is right I think

Answer 2

One word substitution for - incapable of being heard is - inaudible.

•One word substitution is a part of vocabulary of language.

•Here a sentence or many words are replaced with one word.

•That one word defines that whole sentence.

•In the above sentence, it is said the sound can not be heard.

•It is called inaudibility.

•Inaudibility is defined as "the quality of not being perceptible by the ear."