High-frequency hearing loss

Patient's question:

No

Doctor's answer:

Hello, to continue with the examination and treatment, here is the relevant information:
The Rinne test can be conducted in a doctor's office, but the hearing level is best measured by an audiologist using an electroacoustic audiometer that can emit different tones and volumes. In adults, air conduction hearing can be tested by placing a vibrating tuning fork at the ear canal opening, with the sound traveling through the air to the inner ear. Hearing loss or below the normal hearing threshold (threshold is the minimum intensity at which sound can be heard) indicates a lesion in some part of the auditory organ, such as the outer ear canal, middle ear, inner ear, auditory nerve, or the auditory center in the brain.
The bone conduction test in adults involves placing the vibrating handle of the tuning fork on the head, with the vibration transmitted through the skull to the bony cochlea in the inner ear. The cochlear hair cells convert the vibration into neural impulses, which then travel along the auditory nerve to the auditory center. This test excludes the effects of the outer and middle ear and only involves the inner ear, auditory nerve, and auditory pathways in the brain. Different frequency tuning forks should be used during the test, as some patients may only hear specific frequencies.
If air conduction hearing decreases but bone conduction hearing is normal, the hearing loss is conductive. If both air and bone conduction hearing decrease, the hearing loss is sensorineural. Sometimes, hearing loss may have both conductive and sensorineural components.
Audiometry is used to precisely measure the degree of hearing loss. An electroacoustic audiometer can emit pure tones of different frequencies and adjust the volume. By reducing the volume of a specific frequency, the minimum sound intensity that can be heard is the threshold for that frequency. The test is performed on both ears separately. Air conduction is measured using headphones, while bone conduction is measured by placing a vibrating headset on the mastoid bone. Because louder sounds can travel through the skull to the other ear, noise masking is required for the non-tested ear to ensure the measured hearing is the true hearing of the tested ear.
The speech reception threshold test assesses the patient's ability to understand words. A series of disyllabic words, such as "railway," "stairs," or "basketball," are given. The speech reception threshold is the sound intensity at which half of the given words can be understood.
The speech discrimination threshold test measures the ability to distinguish similar-sounding words. Similar monosyllabic words are given, and the percentage of correct repetitions is recorded. In conductive hearing loss, the speech discrimination threshold is usually within the normal range, while in sensorineural hearing loss, it is often below normal, and in neural hearing loss, it is significantly below normal.
Tympanometry is a method to measure the compliance of the middle ear (its ability to transmit and resist sound waves) and is commonly used to identify factors or causes of conductive hearing loss. This test does not require active participation from the patient and is often used for children in clinical settings. A microphone and a speaker that emit continuous sound are placed in the ear canal, and the instrument measures the ability of sound to transmit under changes in ear canal pressure. The results can indicate whether the eustachian tube is open, whether there is fluid in the middle ear, or whether the ossicular chain is disrupted.
Tympanometry can also assess the stapedial reflex. The stapedius muscle is connected to the stapes and normally contracts reflexively in response to loud sounds (sound reflex) to reduce sound transmission and protect the inner ear. In cases of neural hearing loss, the sound reflex may be altered or delayed. When the sound reflex is delayed, the stapedius muscle cannot maintain sustained contraction during continuous sound stimulation.
Auditory brainstem response (ABR) testing is a method to distinguish between sensorineural or neural hearing loss. It detects neural impulses from the auditory nerve to the brainstem. The neural impulse patterns are computer-generated by superimposition. If the cause of hearing loss is in the brainstem or brain, a magnetic resonance imaging (MRI) scan of the head should be performed.
Electrocochleography detects the electrical activity of the cochlea and auditory nerve. Electrocochleography and ABR testing can be used for patients who cannot actively cooperate, such as infants and children, as well as for those with pseudo-hoarding or exaggerated hearing loss (psychogenic deafness). Sometimes, these tests can help determine the cause or nature of sensorineural hearing loss. ABR can also be used to monitor brain function in comatose patients or those undergoing brain surgery.
Certain hearing tests can assess diseases of the brain's auditory center. These tests measure the brain's ability to integrate and understand speech. For example, the ability to understand signals from one ear while competing signals are given to the other ear; the ability to fuse incomplete signals from both ears into meaningful signals; or the ability to locate the sound source when sounds are presented to both ears simultaneously. Because the auditory nerve pathways cross to the opposite side of the brain, abnormal function on one side of the brain can lead to dysfunction in the opposite ear. When the brainstem is injured or affected, the ability to fuse incomplete signals into meaningful signals is impaired, but the ability to accurately locate the sound source remains intact.
Treatment for hearing loss depends on its cause. For example, if conductive hearing loss is caused by fluid in the middle ear or earwax blockage in the outer ear canal, the fluid should be drained or the earwax removed. For patients who do not respond to treatment, hearing compensation should be provided as much as possible. Most people use hearing aids, while a few use cochlear implants.