![]() The Rinne test is intended to detect unilateral hearing loss. The "ticking watch" test is also a high-frequency test. This method fails when patients pretend to hear. One rubs one's fingers together, and records how far away from the ear the patient can hear. The "rubbed fingers" test is another quick way to test high-frequency hearing. More practically, one can screen hearing at high frequencies very quickly with one's hands or analog watch. Patients who have severe hearing loss may have "deaf speech', which is a characteristic pattern of impaired pronounciation related to loss of aural feedback. Similarly, persons in rooms with considerable ambient noise may speak at elevated volumes. Often patients who can't hear themselves, will speak louder. Patients who appear to miss more than others, may have hearing loss. The first and simplest is to simply correlate understanding with speech input, observing whether the patient answers appropriately to questions when the examiner's voice is soft or loud, or with the head turned away or towards the patient. Kelly et al (2018), did a systemic review and observed that there was immense variability in the reports of the reliabilty of bedside tests. We think that in general, these tests are inferior to formal audiometry, and this is greatly preferred when quickly available. B, In the presence of a sensorineural loss, the sound is heard better on the opposite (unaffected) side.There are several ways to evaluate hearing at the bedside. A, In the presence of a conductive hearing loss, the sound is heard on the side of the conductive loss. When a vibrating tuning fork is placed on the center of the forehead, the normal response is for the sound to be heard in the center, without lateralization to either side. Rinne: Right ear: AC > BC ( Rinne positive) left ear: AC > BC (Rinne positive) Weber: Lateralization to the left ear Diagnosis: Right sensorineural deafnessįigure 11-13 The Weber test. ![]() In summary, consider the following two examples: The Rinne and Weber tests are then carried out as indicated, using the silent tuning fork. To test the reliability of the patient's responses, it is occasionally useful to strike the tuning fork against the palm of the hand and hold it briefly to silence it. In patients with unilateral sensorineural deafness, the sound is not heard on the affected side but is heard by, or localized to, the unaffected ear. Thus, the affected ear hears and feels the vibrating tuning fork better than does the normal ear. In an ear with a conductive hearing loss, the air conduction is decreased, and the masking effect is therefore diminished. ![]() This tends to mask the sound of the tuning fork heard by bone conduction. In normal conditions, there is considerable background noise, which reaches the tympanic membrane by air conduction. The explanation for the Weber test effect is based on the masking effect of background noise. The Weber test is illustrated in Figure 11-13. You have created a conductive hearing loss on the right by blocking the right canal the sound is lateralized to the right side. Occlude your right ear and place a vibrating tuning fork in the center of your forehead. Sound is lateralized to the affected side in conductive deafness. If the sound is not heard in the middle, the sound is said to be lateralized, and thus a hearing loss is present. Hearing the sound, or feeling the vibration, in the middle is the normal response. Ask the patient to indicate whether he or she hears or feels the sound in the right ear, in the left ear, or in the middle of the forehead. Stand in front of the patient and place a vibrating 512-Hz tuning fork firmly against the center of the patient's forehead. In the Weber test, bone conduction is compared in both ears, and the examiner determines whether monaural impairment is neural or conductive in origin. ![]()
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