This is used in transmitting the spirit of Shakespeare, by the sound of it (6)
I believe the answer is:
aerial
'this is used in transmitting' is the definition.
The definition suggests a singular noun which matches the answer.
'spirit of shakespeare by the sound of it' is the wordplay.
'spirit of shakespeare' becomes 'ariel' (I've seen this before).
'by the sound of it' indicates a 'sounds like' (homophone) clue.
'ariel' sounds like 'AERIAL'.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for aerial that I've seen before include "Signal receiver" , "Transmitting structure" , "Device to send and receive radio signals" , "imaginary" , "Device for sending or receiving signals" .)