Sounds echoed, drowning start of scheduled meeting (7)
I believe the answer is:
session
'scheduled meeting' is the definition.
'session' can be an answer for 'meeting' (session is a kind of meeting). I'm not sure about the 'scheduled' bit.
'sounds echoed drowning start' is the wordplay.
'sounds' becomes 'noises' (noise is a kind of sound).
'echoed' says the letters should be written in reverse (I've seen 'echoing' mean this (echo can mean to reflect or bounce back)).
'drowning' is an insertion indicator (inserted letters are drowned or absorbed).
'start' becomes 's' (this could be a standard abbreviation of which I'm unaware).
'noises' written backwards gives 'sesion'.
'sesion' going around 's' is 'SESSION'.
'of' is the link.
Can you help me to learn more?
(Other definitions for session that I've seen before include "Period of business for official body" , "Meeting or series of meetings" , "Parliamentary period" , "Period spent on a single activity" , "School term" .)