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 tell whether this definition 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' put 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" .)