The
vocal fry register (also known as
pulse register,
laryngealisation,
pulse phonation,
creak,
croak,
popcorning,
glottal fry,
glottal rattle,
glottal scrape, or
strohbass) is the lowest
vocal register and is produced through a loose
glottal closure which will permit air to bubble through slowly with a popping or rattling sound of a very low frequency. During this
phonation, the
arytenoid cartilages in the
larynx are drawn together which causes the
vocal folds to compress rather tightly and become relatively slack and compact. This process forms a large and irregularly vibrating mass within the vocal folds that produces the characteristic low popping or rattling sound when air passes through the glottal closure. The register (if well controlled) can extend far below the
modal voice register, in some cases up to 8 octaves lower, such as in the case of
Tim Storms who holds the world record for lowest frequency note ever produced by a human, a G-7, which is only 0.189Hz. Humans however can only hear sounds down to 12Hz under ideal conditions.