Brain and Behavior / Week 2
March 21, 2010
Presbycusis is the loss of hearing that gradually occurs in most individuals as they grow older. hearing loss is a common disorder associated with aging. About 30-35 percent of adults between the ages of 65 and 75 years have a hearing loss. It is estimated that 40-50 percent of people 75 and older have a hearing loss. The loss associated with presbycusis is usually greater for high-pitched sounds. For example, it may be difficult for someone to hear the nearby chirping of a bird or the ringing of a telephone. However, the same person may be able to hear clearly the lowpitched sound of a truck rumbling down the street. There are many causes of presbycusis. Most commonly it arises from changes in the inner ear of a person as he or she ages, but presbycusis can also result from changes in the middle ear or from complex changes along the nerve pathways leading to the brain. Presbycusis most often occurs in both ears, affecting them equally. Because the process of loss is gradual, people who have presbycusis may not realize that their hearing is diminishing (Presbycusis, 2002).
In sensory loss (touch, mobility, vision, hearing) this can have a negative impact to an individual like for example in mobility an individual can experience poor mobility, leaning to one side or difficulty with their coordination, the individual may have difficulty to feed or dress themselves, or may not be able to participate in an activity and in some circumstances an individual may not be able ...
Sound is transmitted from the environment to the inner ear via the outer, middle, and inner ear. The first step is the pinna must capture the sound and the sound must reach a smaller area, called the auditory canal. The impact of sound hitting the eardrum creates vibrations that cause three bones in the middle ear to move. The malleous (hammer), incus (anvil), and stapes (stirrups).
The three bones cause movement of the oval window between the middle and inner ear. When the oval vibrates, fluid in the inner ear transmits the vibrations into the hearing organ, called the cochlea (Mayo, 2010).
In the inner ear, thousands of microscopic hair cells are bent by the wavelike action of fluid inside the cochlea. The bending of these hairs sets off nerve impulses that are then passed through the auditory nerve to the hearing center of the brain. This center translates the impulses into sounds the brain can recognize (Mayo, 2010).
When sound waves are converted to neural signals auditory signals also follow the dorsal stream or the ventral stream. The ventral system is responsible for an individual’s and the ability for distinguishing different sounds. This leads to frequency or pitch. Sound is produced whenever there is a disturbance in the position of air molecules. The speed of the variations of air pressure determines the fundamental frequency of sounds. The frequency of sound is perceived by the hearer as pitch (Robbins, n.d.).
Outer / middle ear problems can be caused by reduced function of the tympanic membrane, or reduced function of the malleous, incus, and stapes in the middle ear, that carry sound waves from the tympanic membrane to the inner ear.
Inner ear problems may be a result from a loss of hair cells (sensory receptors in the inner ear).
Another factor may be a result of hereditary factors as well as aging, various health conditions, and side effects of some medicines, such as aspirin, and certain antibiotics (Presbycusis, 2002).
Due to the gradual loss of hearing steps can be taken to aid in communication, some tips are: face the person who has a hearing loss so that he or she can see your face when you speak. Be sure that lighting is in front of you when you speak. This allows a person with a hearing impairment to observe facial expressions, gestures, and lip and body movements that provide communication clues. During conversations, turn off the radio or television. Avoid speaking while chewing food or covering your mouth with your hands. Speak slightly louder than normal, but don’t shout. Shouting may distort your speech. Speak at your normal rate, and do not exaggerate sounds. Clue the person with the hearing loss about the topic of the conversation whenever possible. Rephrase your statement into shorter, simpler sentences if it appears you are not being understood. In restaurants and social gatherings, choose seats or conversation areas away from crowded or noisy areas (Presbysusis, 2002).
Cochlear Implants A cochlear implant is an electronic device that restores hearing for people anywhere from hard of hearing to the profoundly deaf. The cochlear implant is surgically implanted under the skin behind the ear. The surgeon puts the electrode array inside the inner ear and than inside the cochlea. The implant works by a device outside the ear, which rests on the skin behind the ear. It ...
Limitations on Activities
Any activity that requires the sense of hearing, i.e., listening to music, television, or bird watching where one would listen to specific calls of foul to identify them and direct them for a visual sighting.
Affect on Occupation
Although most taking their hearing for granted, it is a necessary component for some occupations. Firefighters must be able to hear alarms, take orders and execute them. Policeman would certainly require hearing for radio transmissions. A loss of hearing might contribute to early retirement, or an occupational fatality.
Mayo Clinic. (2010).
Hearing Disorders. Retrieved March 21, 2010, from: http://
Improving The Lives of People Who Have Communication Disorders.
Retrieved March 21, 2010, from: http://www.nidcd.nih.gov/health/hearing/presbycusis.
Robbins, J. (n.d.).
How Humans Process Language. Retrieved March 21, 2010, from: http://