DictionarywarbleTrilling sound
noun / verb

warble

WOR-bul/ˈwɔːrbl/

A song or sound with rapidly varying notes, or to produce it.

The man warbles into the microphone as his voice rises and falls repeatedly.

An older man sings into a microphone while a nearby live pitch display traces repeated rises and falls, making the wavering quality of his singing visible rather than relying on an open mouth alone.
Etymology

Werbler described singing with trills and quavers. English’s earliest recorded use referred to a trumpet, showing that the central idea was wavering musical sound, not exclusively vocal song.

In context

Libranima181:24
gay- plumaged birds of all sorts began to warble in the trees
Don Quixote - Cervantes (Illustrated Audiobook) Part 3 of 4

More examples

  • She warbles a cheerful tune as she washes the dishes.
  • The bird's warble rises above the noise of traffic.
  • The radio gives a brief warble before the signal fades.

Forms

warble · warbles · warbled · warbling

warbler noun — A small songbird known for its singing.

Similar words

trill
Emphasizes rapid alternation between two notes rather than broader variations.
quaver
Emphasizes a trembling sound rather than a melodious series.