Stenographer's instrument (8)
I believe the answer is:
recorder
I believe this is a double definition.
'stenographer's' is the first definition.
(thesaurus)
'instrument' is the second definition.
(recorder is a kind of instrument)
(Other definitions for recorder that I've seen before include "Wind instrument - historian, perhaps" , "Woodwind instrument; official" , "Annalist" , "Musical instrument or note-taker" , "Fipple-flute" .)