Hearing impairment, known in the technical jargon as hypacusis, refers to a hearing impairment. It affects more and more people and can range from mild impairment to complete hearing loss.
Some complaints are only noticeable for a certain time, others are permanent. Hearing impairment can have many causes. Often it comes with the age of the patient or as a result of illness or noise exposure. In some cases, hearing loss is also inherited. A simple and quick suspected diagnosis is already possible with the resources available in the family doctor's practice. Various tuning fork tests, for example, give the doctor reliable information about which part of the ear could be causing a hearing impairment. This test using a tuning fork also includes the Weber attempt.
A tuning fork test that is used daily in medical practices because of its uncomplicated application is the Weber test.
A tuning fork test that is used daily in medical practices because of its uncomplicated application is the Weber test. Namesake is Ernst Heinrich Weber. As a professor of anatomy and physiology in Leipzig, he drew attention to this method as early as 1834. As a standard test of ear, nose and throat medicine to examine a hearing impairment, this procedure can quickly and effectively narrow down possible causes of hearing loss.
Hearing impairment can result from disorders in the external auditory canal, in the middle or inner ear, but also centrally in the area of the auditory pathway. Depending on where the disorder originated, the hearing loss is divided into sensorineural disorders (damage to the inner ear or area of the auditory nerves) and sound conduction disorder (impairment in the middle ear or external auditory canal). The extent of a hearing impairment can range from a slight hearing loss to deafness.
The Weber experiment allows a good diagnosis of one-sided hearing impairment and is particularly suitable for differentiating between sound conduction and sound sensation disorders. The examination is an uncomplicated and painless process and belongs to the so-called subjective test procedures, since it depends on the active cooperation of the patient. The Weber test usually helps determine which part of the ear is causing the hearing impairment. The doctor uses a tuning fork for this clinically oriented hearing test.
With the help of the tuning fork, the doctor is able to recognize and localize different hearing problems. This method is based on the sound conduction theory of Mach: If the transmission of the sound via the ossicular chain is disturbed in the case of conductive hearing loss, the sound arriving via the bone conduction in the middle ear remains trapped there and is not transmitted.
For diagnosis, the doctor uses the same tuning fork as a musician uses to tune his instrument. It vibrates in concert pitch a with 440 Hertz. The doctor can use it to examine whether a tone generated with the tuning fork is passed on via the head bones and perceived by the patient. The tuning fork is set in motion and placed on the patient's head with the foot. The sound is then passed on to the inner ears via the bone conduction.
If everything is okay with your hearing, the vibrations of the tuning fork are registered equally in both ears. If there is a problem, the sound will appear louder in one ear than in the other. In this way, disturbances in the air conduction can be identified, for example a narrowing of the ear canal or a loss of intensity in the middle ear. The affected person reports that the ear, with which he hears less well, hears the sound particularly loud.
This phenomenon is easy to understand: if you cover one ear, you hear your own spoken word particularly loudly in this ear. With its correct interpretation, the Weber experiment allows an orienting classification of the type of hearing loss. A person with normal hearing or a patient who is equally hard of hearing hears the sound of the tuning fork after placing it on the skull with both ears at the same level. Even the normal hearing person registers the sound of the tuning fork as the same in both ears. He therefore has the impression of hearing this in the middle of his head.
The sound is not lateralized, i.e. not directed to one side. If the patient says they can hear the sound on one side, it is called lateralization. In this case, there is a unilateral or asymmetrical hearing impairment. In the case of a one-sided sensorineural disorder, the sound is perceived louder by the better hearing inner ear, so the patient lateralises into the healthy ear. With a one-sided sound conduction disorder, however, the sound in the affected ear is heard louder, usually to the amazement of the patient.
Conductive hearing loss occurs when the sound is not passed on in the outer or middle ear. Ear wax or otitis media can be responsible for this. If there is conductive hearing loss, the sound in the affected ear is perceived as louder. In the case of sensorineural hearing loss, the sound arrives better in the unaffected ear. Sensorineural hearing loss can be caused by damage to the inner ear, auditory nerve or brain.
The diagnosis in this case can be acute hearing loss, Menière's disease (disease of the inner ear), damage to the inner ear or the auditory nerve, an acoustic neuroma (a benign tumor on the equilibrium and auditory nerves) or a traumatic injury from a skull base fracture. Often, acute sensorineural hearing loss can also be triggered as part of a pop trauma or arise without known causes. The most common trigger for conductive hearing loss is a ceruminous plug, or ear wax. Significant symptoms are acute hearing loss accompanied by a feeling of pressure to ear pain.
In the case of lateralization in the Weber experiment, the doctor will follow up with another tuning fork test, the Rinne experiment. In this way, the cause of hearing impairment can be narrowed down and more precisely determined. The tuning fork test is harmless to health.