The most common and most likely answer to this crossword clue is the 5 letter word AUDIO
I've seen this crossword clue in The Guardian
A
U
D
I
O
More clues leading to the result AUDIO
- Car wheel's sound
- Car’s first for outstanding sound
- Endlessly check one's first sound system
- Sound uniform on girl wearing a ring
- Sound of Monteverdi, perhaps, not 10CC?
- Sound of car 8
- Sound system adds nothing to car
- Opening of Abbey Road erased from studio recording
- A one-sided statement of intent over sound reproduction
- Sound car going over circuit
Buddy explains!

The straight part
We know that "Sound" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sound = audio.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 AUDIO mean?
AUDIO noun- A sound, or a sound signal
- Focused on audible sound, as opposed to sight.