Train voice (7)
I believe the answer is:
express
I believe this clue is a double definition.
'train' is the first definition.
(express is a kind of train)
'voice' is the second definition.
(I've seen this before)
(Other definitions for express that I've seen before include "Utter - direct" , "Train; utter" , "Explicit" , "Utter - non-stop" , "This train doesn't stop" .)