Question

two lists of pleasant and unpleasant sounds

Answer 1

Answer:

example pleasant sound: sound of a river flowing , water fall sound , sound of birds like cuckoo etc. example of unpleasant sound:  the sound at construction site , horn of train.

Answer 2

sound of a river flowing , water fall sound , sound of birds like cuckoo etc. example of unpleasant sound can be. the sound at construction site , horn of train and other vehicles , rock music etc.