Heston Blumenthal has investigated how sound affects chewing, but I didn’t know that sound was so important for how we perceive the taste of apples. Studying particularily crisp apples, named Jazz apples, researchers found the following:
Professor Povey said, “When you munch a Jazz apple you create pulses of sound containing large amounts of ultrasound which our brains interpret differently from ordinary sounds such as speech. The pulses are so intense that if they were sustained as a tone, they would destroy our hearing.”
“It appears that ordinary hearing is short-circuited somehow and the greater the number of pulses of sound, the crisper we think the food is. Ultrasound is sound that is beyond the range of normal human hearing but it helps shape the noise into pulses that sound quite different.
“Our group of subjects were culturally diverse but all were able to identify crispness similarly. So perhaps there is a genetic disposition to the appreciation of crispness which has evolved as a sign of freshness in food.”