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2 Responses to “What is the difference between a cochlear hearing loss and a neural hearing loss?”
Sensory hearing loss is secondary to disturbance of the cochlea; neural hearing loss results from disease of the auditory (eighth) nerve or central auditory channel connections.
Tone decay test: This test involves the presentation of a continuous tone and determination that the threshold for the tone has changed (becomes poorer) over time. The test helps differentiate sensory from neural hearing loss, and is used in the diagnosis of cochlear versus retrocochlear lesions and eighth nerve tumors. While this test is still in use, the brain stem auditory evoked response (BAER) test is largely used in place of the tone decay test.
Sensorineural acuity level (SAL) test: This test measures the extent of sensorineural hearing loss and is also utilized in the detection of pseudohypoacusis (hypacusis is a hearing impairment of a conductive or a neurosensory nature and pseudohypoacusis is a non-existent [false] hearing loss) among children. It is not a commonly performed test. There are several different tests in use, including one where a bone-conduction vibrator is placed at the center of the forehead and the threshold shift for a normal ear versus an ear with sensorineural hearing loss is analyzed.
Pure tone audiometry, air and bone conduction: This test is a standard audiometric study and utilizes tones of various frequencies and intensities as auditory stimuli to measure hearing. Air conduction is the usual method of sound transmission and air audiometry utilizes the external and middle ear in the transmission of sound to the cochlear and beyond. Bone conduction audiometry involves the vibration of the skull by direct contact with an oscillating device which is thought to set the cochlear fluids into motion, bypassing the external and middle ear. When bone conduction thresholds are better than air conduction thresholds, the loss is conductive. When bone conduction thresholds are the same as air conduction thresholds, the loss is sensorineural. When bone conduction thresholds are reduced but are still better than air conduction, the loss is mixed or combined.
Acoustic reflex test: This test is a measurement of the changes in the ear’s ability to conduct sound to the cochlea. Reflexes, called acoustic reflexes, exist which involve middle ear function. Absence of the acoustic reflex may be indicative, among other things, of lesions of the middle ear, acoustic tumor, otosclerosis, facial nerve involvement of the probe ear side, and surgical removal or congenital absence of the stapes, and may be used in assessing the hearing of neonates and other children too young to cooperate in the audiometric testing of functional hearing loss.
Acoustic reflex decay test: This test involves continuous stimulation and length of time that the acoustic reflex is present and may assist in the diagnosis of an eighth nerve tumor.
Brain stem auditory evoked potentials (BAEP): This is an electrophysiologic measure of auditory function utilizing responses produced by the auditory nerve and the brain stem and helps differentiate sensory from neural hearing loss. The response is the waveform averaged over many auditory clicks. It may be helpful in the diagnosis of cerebellopontine angle tumors and acoustic neuromas, is used as a monitor in posterior fossa surgery, and may help to establish a hearing threshold for infants and difficult-to-test patients.
There is not much difference between sensory (cochlea) and neural (nerve) hearing loss in fact it is categorized together as sensorineural. Sensory hearing loss is due to damage in the cochlea usually from noise exposure, or the natural aging process people start to lose some of the cells in the cochlear over time. Neural hearing loss affects the hearing nerve. Most commonly this is due to a tumor pressing on the auditory nerve in the brain. When I do a hearing test I look at the results and if they are abnormal and a suspected neural problem exists I refer to an ENT who will hopefully schedule an MRI to rule out a tumor on auditory nerve. I take a conservative approach and look for a difference between the two ears either from the tone test or the word understanding test. Usually there is only a tumor on the one side so one ear tests worse than the other.
The tests the person described above do provide useful information, but cannot accurately say whether the problem is in cochlea or nerve. Really need an MRI to rule out tumor.
July 2nd, 2009 at 1:24 am
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Sensory hearing loss is secondary to disturbance of the cochlea; neural hearing loss results from disease of the auditory (eighth) nerve or central auditory channel connections.
Tone decay test: This test involves the presentation of a continuous tone and determination that the threshold for the tone has changed (becomes poorer) over time. The test helps differentiate sensory from neural hearing loss, and is used in the diagnosis of cochlear versus retrocochlear lesions and eighth nerve tumors. While this test is still in use, the brain stem auditory evoked response (BAER) test is largely used in place of the tone decay test.
Sensorineural acuity level (SAL) test: This test measures the extent of sensorineural hearing loss and is also utilized in the detection of pseudohypoacusis (hypacusis is a hearing impairment of a conductive or a neurosensory nature and pseudohypoacusis is a non-existent [false] hearing loss) among children. It is not a commonly performed test. There are several different tests in use, including one where a bone-conduction vibrator is placed at the center of the forehead and the threshold shift for a normal ear versus an ear with sensorineural hearing loss is analyzed.
Pure tone audiometry, air and bone conduction: This test is a standard audiometric study and utilizes tones of various frequencies and intensities as auditory stimuli to measure hearing. Air conduction is the usual method of sound transmission and air audiometry utilizes the external and middle ear in the transmission of sound to the cochlear and beyond. Bone conduction audiometry involves the vibration of the skull by direct contact with an oscillating device which is thought to set the cochlear fluids into motion, bypassing the external and middle ear. When bone conduction thresholds are better than air conduction thresholds, the loss is conductive. When bone conduction thresholds are the same as air conduction thresholds, the loss is sensorineural. When bone conduction thresholds are reduced but are still better than air conduction, the loss is mixed or combined.
Acoustic reflex test: This test is a measurement of the changes in the ear’s ability to conduct sound to the cochlea. Reflexes, called acoustic reflexes, exist which involve middle ear function. Absence of the acoustic reflex may be indicative, among other things, of lesions of the middle ear, acoustic tumor, otosclerosis, facial nerve involvement of the probe ear side, and surgical removal or congenital absence of the stapes, and may be used in assessing the hearing of neonates and other children too young to cooperate in the audiometric testing of functional hearing loss.
Acoustic reflex decay test: This test involves continuous stimulation and length of time that the acoustic reflex is present and may assist in the diagnosis of an eighth nerve tumor.
Brain stem auditory evoked potentials (BAEP): This is an electrophysiologic measure of auditory function utilizing responses produced by the auditory nerve and the brain stem and helps differentiate sensory from neural hearing loss. The response is the waveform averaged over many auditory clicks. It may be helpful in the diagnosis of cerebellopontine angle tumors and acoustic neuromas, is used as a monitor in posterior fossa surgery, and may help to establish a hearing threshold for infants and difficult-to-test patients.
Hope this helps.
July 3rd, 2009 at 4:21 pm
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There is not much difference between sensory (cochlea) and neural (nerve) hearing loss in fact it is categorized together as sensorineural. Sensory hearing loss is due to damage in the cochlea usually from noise exposure, or the natural aging process people start to lose some of the cells in the cochlear over time. Neural hearing loss affects the hearing nerve. Most commonly this is due to a tumor pressing on the auditory nerve in the brain. When I do a hearing test I look at the results and if they are abnormal and a suspected neural problem exists I refer to an ENT who will hopefully schedule an MRI to rule out a tumor on auditory nerve. I take a conservative approach and look for a difference between the two ears either from the tone test or the word understanding test. Usually there is only a tumor on the one side so one ear tests worse than the other.
The tests the person described above do provide useful information, but cannot accurately say whether the problem is in cochlea or nerve. Really need an MRI to rule out tumor.