Introduction
The human auditory system is incredibly accurate in identifying signal content, location, and meaning through discrete neurological processes. The accuracy of these processes begins at the external, anatomical portions of the auditory pathway: the pinna and ear canal. The pinna serves to collect sound from the environment and generate direction-dependent cues through spectral transformations (Hofman, et al, 1998; Raykar, et al, 2005). Sounds that are funneled into the ear canal contain a range of frequencies that are amplified and attenuated. This interaction of complex sound waves, based on the unique shape of an individual’s pinna, results in a transfer function used for localization in the vertical plane (Hofman, et al, 1998, p. 417). There is evidence that the spectral notches and peaks formed when sound interacts with the pinna are key component to localization of sound in the vertical plane (Raykar, et al, 2005, p. 364). The spectral changes caused by reflections of sound waves on the unique curves of the pinna are referred to as “spectral patterning”. This occurs primarily in frequencies above 6 kHz, as the wavelength of the sound is short enough for it to interact with the pinna. This indicates that sound localization is influenced most by high-frequencies (Moore, 2007, p. 186).
Each individual ear is unique and provides frequency information not offered by any other facet of the auditory pathway. The distinctive curvature and overall shape of the pinna aids in shaping complex signals to determine spatial information by integrating the frequency transforms for both ears. Therefore, it is important to be capable of receiving sound binaurally to accurately locate the signal in space and to reduce ambiguity wit...
... middle of paper ...
...
References
Hofman, P. M., Van Riswick, J. G., & Van Opstal, A. J. (1998). Relearning sound localization with new ears. Nature neuroscience, 1(5), 417-421.
Hone, R. (2010). Pinna augmentation and hearing gain. Otolaryngology--Head and Neck Surgery, 143(2), P243.
Kuk, F., Korhonen, P., Lau, C., Keenan, D., & Norgaard, M. (2013). Evaluation of a pinna compensation algorithm for sound localization and speech perception in noise. American Journal of Audiology, 22(1), 84-93.
Moore, Brian C.J. (2007). Cochlear Hearing Loss: Physiological, Psychological and Technical Issues. England: John Wiley & Sons, Ltd.
Raykar, V. C., Duraiswami, R., & Yegnanarayana, B. (2005). Extracting the frequencies of the pinna spectral notches in measured head related impulse responses. The Journal of the Acoustical Society of America, 118(1), 364-374.
Http://soundjax.com/?q=click+
Technology nowadays is getting more and more dangerous, especially to our ears. Every day we are subjected to videos, text sounds, alert sounds, alarms, and anything else that may be of use in life. These sounds seem to be happening more often which is damaging our ears. There is a solution to this damage though, and that is cochlear implants. These implants will bypass the damaged part of your ear to give you a sense of sound that can be made very useful to the patient. This paper will look into how the ear works, how hearing loss happens, why these cochlear implants are a good solution, how these implants work, cost and ethics related to these implants, and what the future holds for them.
Lane, Harlan (1992). “Cochlear Implants are Wrong for Young Deaf Children.” Viewpoints on Deafness. Ed. Mervin D. Garretson. National Association of the Deaf, Silver Spring, MD. 89-92.
Cochlear Implants only restore very limited audibility. When described by formerly hearing Deaf people they compare it to hearing underwater, “fuzzy and timbre” yet still able to discern some
“Music is perpetual, and only the hearing is intermittent,” wrote the iconic American essayist, poet and philosopher Henry David Thoreau, a lofty proclamation that inspired my focus to help those with hearing loss through restoration. After a winding journey in search for an academic focus, I discovered that audiology is far more than just aiding deaf or hard of hearing individuals, but restoring balance, managing loss through therapy, and discovering new research techniques that may involve auditory neuropathy spectrum disorder. After arriving at my destination, I also learned that it is my responsibility as a future audiologist to be a leader, to work hard toward achieving a better future for myself, and a better world for humanity at large. This vision drives my aspiration to join the University of South Florida’s graduate audiology program this coming fall, and continue my examination of clinical audiology as a member of your community.
Audition is a complex process that involves multiple areas of the brain. To be able to hear sound is just the beginning. Understanding speech and appreciating music requires an intensive and complex network of processes still yet to be understood. Many auditory processing deficits have been discovered with varying degrees of specificity and severities. A whole area of research has been dedicated to finding solutions to these auditory deficits that many ...
11. Kim-Cohen, S. 2009. In the Blink of an Ear: Toward a Non-Cochlear Sonic Art
Tanner, D.C. (2003). Chapter 6: Hearing Loss and Deafness. In Exploring communication disorders: A 21st century introduction through literature and media (2nd ed., p.192). Boston, Massachusetts: Allyn and Bacon.
Tucker, Bonnie. “Deaf Culture, Cochlear Implants, and Elective Disability.” Hastings Center Report. 28.4 (1998): 1-12. Academic Search Complete. EBSCO. Web. 9 Dec. 2013.
The mechanical motions of the ossicles directly vibrate a small membrane that connects to the fluid filled inner ear. From this point, vibration of the connective membrane (oval window) transforms mechanical motion into a pressure wave in fluid. This pressure wave enters and hence passes vibrations into the fluid filled structure called the cochlea. The cochlea contains two membranes and between these two membranes, are specialized neurons or receptors called Hair cells. Once vibrations enter the cochlea, they cause the lower membrane (basilar membrane) to move in respect to the upper membrane (i.e. --the tectorial membrane in which the hair cells are embedded). This movement bends the hair cells to cause receptor potentials in these cells which in turn cause the release of transmitter onto the neurons of the auditory nerve. In this case, the hair cell receptors are very pressure sensitive. The greater the force of the vibrations on the membrane, the more the hair cells bend and hence the greater the receptor potential generated by these hair cells.
National Institute on Deafness and Other Communication Disorders. (November 2002). Retrieved October 17, 2004, from http://www.nidcd.nih.gov/health/hearing/coch.asp
This is called the vestibular ocular reflex. These tasks are accomplished through the mechnoreceptors of the three semicircular canals, the utricle and the saccule (3). Like the neighboring auditory system, each canal has hair cells that detect minute changes in fluid displacement, but unlike the auditory system, the utricle and the saccule send information to the brain regarding linear acceleration and head tilt. Shaking your head no employs one of these canals. Likewise, there is a canal that detects head movement in the yes position, and there is yet another semicircular canal that detects motion from moving your head from shoulder to shoulder (4).
National Institute of Health. (2011). National Institute on Deafness and other communication disorders: Improving the lives of people who have communication disorders. National Institute on
It is a well established fact, that during the fetal period, the brain undergoes extensive developmental changes, with new synapses being formed continuously in response to external cues being delivered to the fetus. This development of neuronal connectivity enables the fetus to recognize and analyze complex information. This is especially true in the development of the auditory nervous system. A strong model of the auditory development in response ...
Auditory processing is the process of taking in sound through the ear and having it travel to the language portion of the brain to be interpreted. In simpler terms, “What the brain does with what the ear hears”(Katz and Wilde, 1994). Problems with auditory processing can affect a student’s ability to develop language skills and communicate effectively. “If the sounds of speech are not delivered to the language system accurately and quickly, then surely the language ability would be compromised” (Miller, 2011). There are many skills involved in auditory processing which are required for basic listening and communication processes. These include, sensation, discrimination, localization, auditory attention, auditory figure-ground, auditory discrimination, auditory closure, auditory synthesis, auditory analysis, auditory association, and auditory memory. (Florida Department of Education, 2001) A person can undergo a variety of problems if there is damage in auditory processing . An auditory decoding deficit is when the language dominant hemisphere does not function properly, which affects speech sound encoding. (ACENTA,2003) Some indicators of a person struggling with an auditory decoding deficit would be weakness in semantics, difficulty with reading and spelling, and frequently mishearing information. Another problem associated with auditory processing is binaural integration/separation deficit. This occurs in the corpus callosum and is a result of poor communication between the two hemispheres of the brain. (ACENTA,2003) A person with this will have difficulty performing tasks that require intersensory and/or multi-sensory communication. They may have trouble with reading, spelling, writi...
The ear is looked upon as a miniature receiver, amplifier and signal-processing system. The structure of the outer ear catching sound waves as they move into the external auditory canal. The sound waves then hit the eardrum and the pressure of the air causes the drum to vibrate back and forth. When the eardrum vibrates its neighbour the malleus then vibrates too. The vibrations are then transmitted from the malleus to the incus and then to the stapes. Together the three bones increase the pressure which in turn pushes the membrane of the oval window in and out. This movement sets up fluid pressure waves in the perilymph of the cochlea. The bulging of the oval window then pushes on the perilymph of the scala vestibuli. From here the pressure waves are transmitted from the scala vestibuli to the scala tympani and then eventually finds its way to the round window. This causes the round window to bulge outward into the middle ear. The scala vestibuli and scala tympani walls are now deformed with the pressure waves and the vestibular membrane is also pushed back and forth creating pressure waves in the endolymph inside the cochlear duct. These waves then causes the membrane to vibrate, which in turn cause the hairs cells of the spiral organ to move against the tectorial membrane. The bending of the stereo cilia produces receptor potentials that in the end lead to the generation of nerve impulses.