Doraemon (1979)

The Sonic Oscillation Terror Machine (1x235)

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Doraemon takes out the Sonic Oscillation Terror Machine, which converts high decibel sounds into a sound wave that rids the house of pests. Nobita decides to use Gian's terrible singing and invites him over to his house to sing. Nobita later begins an exterminating company and invites Gian over to their classmates' houses to get rid of the pests with Gian's destructive voice.