This is the 14954th most frequent German word.
schallende
"Schallende" means "resounding" or "ringing" in English.
The word 'schallendem' here is an adjective describing 'Gelächter', indicating the quality as resounding or echoing.
Der Raum erfüllte sich mit schallendem Gelächter.
The room filled with resounding laughter.
In this sentence, 'schallende' describes 'Laute', applying the characteristic of being loud and echoing to the sounds themselves.
Schallende Laute hallten über die Felder.
Resounding sounds echoed across the fields.
Here, 'schallende' modifies 'Ohrfeige', emphasizing the distinct loud noise produced by the slap.