Very loud echo absorbed by book has an impact (7)
I believe the answer is:
affects
'has an impact' is the definition.
I can't judge whether this defines the answer.
'very loud echo absorbed by book' is the wordplay.
'very loud' becomes 'ff' (musical abbreviation for 'fortissimo', very loud).
'echo' becomes 'e' (phonetic alphabet: alpha, bravo, charlie etc.).
'absorbed by' means one lot of letters goes inside another.
'book' becomes 'acts' (book of the Bible).
'ff'+'e'='ffe'
'ffe' going inside 'acts' is 'AFFECTS'.
Can you help me to learn more?
(Other definitions for affects that I've seen before include "Influences" , "Makes a difference to" , "Bears upon" , "Has an effect on" .)