Sound equipment Nigeria had distributed (7,3)
I believe the answer is:
hearing aid
'sound equipment' is the definition.
(equipment for hearing sound)
'nigeria had distributed' is the wordplay.
'distributed' indicates an anagram.
'nigeria'+'had'='nigeriahad'
'nigeriahad' with letters rearranged gives 'HEARING-AID'.
(Other definitions for hearing aid that I've seen before include "Amplifier for ear" , "Help for the partially deaf" , "asset in court?" , "Ear trumpet" , "Earpiece" .)