Means to be heard, entertaining earl with improbable irony, perhaps (8)
I believe the answer is:
metallic
'irony perhaps' is the definition.
I can't tell whether this defines the answer.
'means to be heard entertaining earl with improbable' is the wordplay.
'means to be heard' becomes 'mic' (microphone).
'entertaining' is an insertion indicator (inviting in, as for dinner).
'earl' becomes 'e'.
'with' means one lot of letters go next to another.
'improbable' becomes 'tall' (synonyms).
'e'+'tall'='etall'
'mic' placed around 'etall' is 'METALLIC'.
Can you help me to learn more?
(Other definitions for metallic that I've seen before include "Call time (anag.)" , "This car paint say, gives a shiny surface" , "sound of a bell?" , "Of the nature of tin, iron, copper etc" , "Relating to shiny chemical element" .)