The most common and most likely answer to this crossword clue is the 9 letter word LISTENERS
I've seen this crossword clue in The Daily Telegraph
L
I
S
T
E
N
E
R
S
More clues leading to the result LISTENERS
- Auditors’ audience?
- Inclination, having seen about Romeo, to be all ears
- Play set among cruise ships getting audience
- They follow advice of Frenchman elevated in heels
- Lean to one side and sneer, agitating the audience
- Line one resents playing for radio audience?
- Radio users may get faulty set in ships
- First sign of nonconformance caught by cunning, tireless auditors
- Frolicking, less inert audience
Buddy explains!

The straight part
We know that "radio audience" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case radio audience = listeners.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 LISTENERS mean?
LISTENERS noun- Someone who listens, especially to a speech or a broadcast.
- (chiefly Java) A function that runs in response to an event; an event handler.
- A person's ear.