Sound system in austere office (6)
I believe the answer is:
stereo
'sound system' is the definition.
(stereo is a kind of sound system)
'in austere office' is the wordplay.
'in' indicates the answer is hidden within the clue.
'STEREO' is hidden in the letters of 'austere office'.
(Other definitions for stereo that I've seen before include "Method of sound reproduction" , "Sound transmission through two or more speakers" , "Sound transmitted through two speakers" , "In-depth" , "Three dimensional sound effect" .)