The most common and most likely answer to this crossword clue is the 3 plus 7 letter word EAR TRUMPET
I've seen this crossword clue in The Times
E
A
R
T
R
U
M
P
E
T
More clues leading to the result EAR TRUMPET
- English skill behind film's sound engineering device
- Meat and toasted cake, no starters, help in reception
- Sadly premature, accepting troop leader’s old hearing aid
- With which to pick up sound of jumbo in Bow?
- Behind short film supporting revised rate for hearing aid
- Electronic facility storing President Eisenhower’s first hearing aid
- Sound device in better film, after something corny?
- 8 Regularly repairs musical instrument’s sound amplifier
- Hearing piece produced by organ and wind instrument
- Appalling mutterer? Pa must get a hearing aid!
Buddy explains!
The straight part
We know that "old hearing aid" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case old hearing aid = ear trumpet.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.
Crossword Answer definitions
EAR TRUMPET noun- A conical device designed to channel sound to the apex, placed in the ear to serve as a hearing aid.