wah-wah
noun [ U or C ] uk/ˈwɑː.wɑː/ us/ˈwɑː.wɑː/
（演奏电吉他、短号、小号等时发出的）“哇哇”声;“哇哇”声发生器
a way of changing the sound of notes played on an electric guitar, trumpet, or trombone to make them sound like a human voice saying "wah", or a device that produces this effect