The most common and most likely answer to this crossword clue is the 8 letter word ACOUSTIC
I've seen this crossword clue in The Daily Telegraph
A
C
O
U
S
T
I
C
More clues leading to the result ACOUSTIC
- A firm universal glue reduced soundproofing?
- Relating to sound half of N African dish swallowed in a brief moment
- A bird calls for a moment, heard without amplification
- A stroke of genius; staff spoke of hearing
- A magistrate disrobed after firstly cursing, out of hearing
- Scottish cattle prod, you could say, to do with sound
- A cost cut stupidly, swapping toaster’s lead for current that’s not electric
- A firm has us twitching — is it good if we can hear?
- A Highlander’s cudgel, reportedly not electric
- A stucco I fancy as characteristic of auditorium?
Buddy explains!

The straight part
We know that "is it good if we can hear" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case is it good if we can hear = acoustic.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ACOUSTIC mean?
ACOUSTIC noun- A medicine or other agent to assist hearing.
- Pertaining to the sense of hearing, the organs of hearing, or the science of sounds; auditory.
- Naturally producing or produced by an instrument without electrical amplification, as an acoustic guitar or acoustic piano.
- (retronym) A hollow-body guitar of the older variety, in contradistinction to an electric guitar.