Hearing is sensing the acoustic environment, which is taking acoustic vibrations from the environment and allowing this to travel through the cochlea. The cochlea makes the ear drum vibrate and pushes fluid in the cochlea around, which is in contact with the hair cells in the ear that transduce the vibrations into a signal that gets sent to the brain for interpretation. These hair cells can only respond to a certain range of frequencies. This range of frequencies that humans can hear is relatively narrow in comparison to for example a dog that can hear a wide range of frequencies. Another example of a species with better hearing than humans would be whales, considering they communicate with each other in frequencies below 20, which is much lower frequency than humans can hear. Sadly, whales are having trouble communicating with one another and as a result becoming less prevalent due to the environment now having low rumbles, which doesn’t allow the whales to hear each other. The noise pollution is causing whales to become extinct along with other reasons, because whales rely on sound to find food, like humans rely on sight to find food (“Threats”). These whales also utilize sound to be able to find their communicate with other whales for a means of finding their homes, as a result of not being able to do so, some whales are becoming stranded on the beach as they can’t find their home (“Threats”). As humans get older their hair cells decay and fall out, which causes us to have declining hearing as we age. These hair cells usually do not come back after loosing them. Preferences for hearing are learned and not innate like the preference for sweet tastes. This gives reason why people that live in different areas have different music preferences. For example, if an average American traveled to Finland they would not like the music at all, considering heavy gothic music is a trending popular music in Finland, and in America pop is the music of choice in the teenage community. These preferences were learned from hearing it in the community and previous experiences and are usually learned early in life. These hearing preferences do not change over time.
Touch results from cells slightly under the skin that detect heat, cold, pain, etc, and send nerve impulses to the brain to signal what it is detecting. We have receptors for each type of touch sensation; such as we have Pacinian Corpuscles that detect pressure.
All of these receptors are unique in that they all send a higher concentration of nerve impulses to the brain when the pressure or heat or cold sensation is more intense. The tongue is the best at sensing whether a food product is creamy, powdery, gritty, etc. The tongue can even detect the size of the food molecules coming into contact with the surface of the tongue. People can detect the size of the food particles due to the combination of sensors on the tongue and the flow across the receptors. Although from person to person the detection of texture varies, due to perception and saliva variation in the population.
There are a variety of forms that foods can be in, such as liquids, gases, solids, foams, doughs, etc, and this structure tells the consumers a lot about the quality and sensory attributes of a food product. Food structure can be induced in the food product during preparation, or can be the natural 3D conformation of the food product. Food structure is an accurate determinant of food quality. For example, for bread to have the appropriate structure, the dough must be kneaded for a particular amount of time to develop the gluten and shorten the protein fibers to form a protein matrix.
Therefore, if the dough was not kneaded for the right amount of time the dough will not have that normal structure and may be much more dense or have a lot of air bubbles incorporated into the bread. Therefore, the structure tells the consumer the quality of the bread.
“The Problems With Olestra.” The Problems With Olestra ~ Center for Science in the Public Interest. N.p., n.d. Web. 16 Mar. 2014.
“Threats.” Facing Whale Populations. Vancouver Aquarium, n.d. Web. 16 Mar. 2014.