What does the cryptic crossword clue "Nymph has bedroom that creates sound effects (4,7)" mean?

The wordplay uses a charade (building blocks). ECHO (synonym="nymph") + CHAMBER (synonym="CHAMBER") = ECHOCHAMBER The answer is ECHOCHAMBER.

Nymph has bedroom that creates sound effects (4,7)

Guardian Cryptic #29256 | 3 Down | 2023-12-18 flower