A chirp is scratch

Scratching

Scratching is a DJ or turntablist technique used to produce distinctive sounds by moving a vinyl record back and forth on a turntable while optionally manipulating the crossfader on a DJ mixer. While scratching is most commonly associated with hip hop music, since the late 1980s, it has been used...

, a term used by turntablists

Disc jockey

A disc jockey, also known as DJ, is a person who selects and plays recorded music for an audience. Originally, "disc" referred to phonograph records, not the later Compact Discs. Today, the term includes all forms of music playback, no matter the medium.There are several types of disc jockeys...

. It involves the use of record hand movement and the cross-fader.

Technique

The scratch is somewhat difficult to perform because it takes a good amount of coordination.
The scratch starts out with the cross-fader open. The DJ then moves the record

Gramophone record

A gramophone record, commonly known as a phonograph record , vinyl record , or colloquially, a record, is an analog sound storage medium consisting of a flat disc with an inscribed, modulated spiral groove...

 forward while simultaneously closing the previously opened channel ending the first sound

Sound

Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...

. Then, in a reverse fashion, the DJ opens the channel while moving the record backwards creating a more controlled sounding "baby scratch". Done in quick cession it sounds as though a chirp sound is being produced.