I made this sound by shortening and amplifying the doorbell buzzer on this site. It fits much better into a ...
Standard buzzer sound. Wrong answer, emergency alarm, etc. Synthesized by using very fast alternating tones.
Beating one time on a small (20 cm in diameter) Chinese gong. Vivanco EM35, Marantz PMD671
noisy boom (I used little metal desk)
A dual mono recording of a boxing bell struck once as at the beginning of a round.
A dual mono file of a bell striking three times as at the end of a boxing round.