Falling events by the sound of it (9)
I believe the answer is:
incidence
'falling' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'events by the sound of it' is the wordplay.
'events' becomes 'incidents' (incident is a kind of event).
'by the sound of it' indicates a 'sounds like' (homophone) clue.
'incidents' sounds like 'INCIDENCE'.
Can you help me to learn more?
(Other definitions for incidence that I've seen before include "Rate of occurrence (eg, of a crime)" , "Frequency of occurrence" .)