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Crunchiness is the 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.
Crunchy foods are associated with freshness, particularly in vegetables.[1][2] In bready foods, crunchiness can instead be associated with staleness. Other foods regularly associated with the sensation include nuts[3] and sweets.
Crispness and crunchiness could 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".[4] 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.