Tell the patient that after the tuning fork is on the mastoid, the patient should indicate whether he or she hears a tone. To perform the test, instruct the patient that you will place the tuning fork behind her or his ear on the mastoid process. If there is a conductive loss where the breakdown in function causes an occlusion effect in either or both ears, no difference will be detected between open versus closed ear canal conditions because the disorder itself is already causing an occlusion effect. In the case of normal hearing or sensorineural loss, the patient will perceive a bone-conducted signal as louder when the ear canal is closed versus open due to the occlusion effect. The Bing test is based on the occlusion effect. In some cases, patients are unable to differentiate in which ear the sound was heard, and the test outcome is equivocal.įinally, patients with normal hearing, as well as some with bilateral sensorineural hearing loss, may report hearing the tone in both ears or "all over" the head. Another way to say this is that the tone will localize to the ear with the conductive component or to the ear with the better sensorineural reserve. The patient has a higher sensation level in the opposite ear and will report hearing the sound in that ear, again due to the Stenger effect. Because the occlusion effect creates a higher sensation level, the patient reports hearing the sound in the ear with the conductive hearing loss.įor patients who have a sensorineural hearing loss in one ear, there is no occlusion effect. ![]() Due to the Stenger effect, the patient hears the tone only in the ear with the higher sensation level. When the tuning fork is placed onto the forehead, a tone of the same intensity and phase is presented to both ears simultaneously. It is important to instruct the patient that he or she might hear the tone in the better ear, the worse ear, or possibly somewhere else in the head.įor patients who have a conductive hearing loss in one ear, an occlusion effect is created in that ear, causing a higher sensation level. The patient is instructed to tell the examiner in which ear the tone is heard. For this test, a low-frequency tuning fork is struck, and the base is placed on the forehead or frontal sinuses. The test is based on both the occlusion effect and the Stenger effect. The Weber test is used to determine the presence of a conductive component in the case of unilateral hearing loss. Results from the test should be interpreted with caution. The Shwabach test is rarely used to identify hearing loss due to the wide availability of clinical audiometers. Finally, the patient could have a sensorineural hearing loss if he or she hears the tone for a shorter time period than the examiner. Second, the patient could hear the tone longer than the examiner indicating a conductive hearing loss. First, the patient could have normal hearing by bone conduction. There are three basic outcomes to the test, assuming the examiner has normal hearing. ![]() If the tone decays at a rate of 5dB per second and the clinician has perceived the tone for 6 seconds longer than the patient, it can be determined that the patient has a 30dB HL hearing loss, assuming that the audiometric thresholds for the clinician are at 0 dB HL. To correlate the findings of this test with the pure-tone audiogram, the clinician must know the decay rate of the tuning fork in use. If the tone is still present, the clinician determines how long he or she perceives the tone beyond that of the patient. The clinician then places the fork on his or her own mastoid process to determine the presence of the tone. The patient informs the clinician when the tone is no longer heard. The tuning fork is struck and placed on the mastoid of the patient. The frequency of the tuning fork used for this test is chosen based on the frequency at which hearing loss is suspected. ![]() The Schwabach Test is a technique for estimating a patient's hearing sensitivity by bone-conduction.
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