Tear off lid and gulp down contents, it softens the sound (7)
I believe the answer is:
earplug
'tear off lid' is the definition.
The definition suggests a singular noun which matches the answer.
'gulp down contents it softens the sound' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'gulp' is 'plug' which is located in the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is found within the answer.
The remaining letters 'ar' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'and' is the link.
Can you help me to learn more?
(Other definitions for earplug that I've seen before include "Device to keep out noise" , "Noise defender" , "Hearing protector" , "It keeps out noise" , "protection for delicate drum" .)