Synonyms for chirp

Most common

1. Peep

peep, cheep, chirrup

Other

sing, twitter, pip, carol, tweedle, chirr, stridulate

v. 1
To make a short, sharp, cheerful note, as of small birds or crickets; to chitter; to twitter.

Past participle: chirped
e.g. chirped → peeped, cheeped, chirruped, twittered…

or Chirp?

To chirp is to utter a brief musical sound, perhaps often repeated in the same key, as by certain small birds, insects, etc.

J. C. Fernald, English Synonyms and Antonyms (1914)

peep I don't want to hear another peep out of you.
chirrup For an hour or more that evening I listened to his monotonous chirrup.
sing You are the kind of guitarist I like to sing with.

Use in printed books, per decade from 1850 to 2019.

The small number after each word is its number of syllables (carol² = 2 syllables).