Turn up the volume and confuse Sonic with other online characters (9)

I believe the answer is:

emoticons

I'm a little stuck... Click here to teach me more about this clue!

'other online characters' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.

'turn up the volume and confuse sonic' is the wordplay.
'turn up' is a reversal indicator.
'the volume' becomes 'tome' (a tome is a large or heavy book).
'and' says to put letters next to each other.
'confuse' indicates an anagram.
'tome' in reverse letter order is 'emot'.
'sonic' is an anagram of 'icons'.
'emot'+'icons'='EMOTICONS'

'with' acts as a link.

Can you help me to learn more?

(Other definitions for emoticons that I've seen before include "symbols" , "facial expressions" .)

I've seen this clue in the Sydney Morning Herald.

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