Crunchiness is the gustatory sensation of muffled grinding of a foodstuff. Crunchiness differs from crispness in that a crisp item is quickly atomized, while a crunchy one offers sustained, granular resistance to jaw action. While crispness is difficult to maintain, crunchiness is difficult to overcome.
Vickers (1981) and Christensen and Vickers (1981) aver that crispness and crunchiness can each be "assessed on the basis of sound alone, on the basis of oral-tactile clues alone, or on the basis of a combination of auditory and oral-tactile information." They also note that an acoustic frequency of 1.9 kHz seems to mark the threshold between the two sensations, with crunchiness at frequencies below, and crispness at frequencies above.
Crunchy foods include: