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Tuning Fork Tests
Area of applicationEars.
A tuning fork is a bipronged metallic device that emits a clear tone at a particular pitch when it is set into vibration by holding the stem in the hand and striking one of the prongs or tines against a firm surface. The Bing test samples for conductive hearing loss by intermittently occluding and unblocking the opening of the ear canal while holding a vibrating tuning fork to the mastoid process behind the ear. The occlusion effect is absent in patients with conductive hearing loss and is present in patients with normal hearing or with sensorineural hearing loss. The Rinne test compares the patient’s own hearing by bone conduction to his or her hearing by air conduction to determine whether hearing loss, if detected, is conductive or sensorineural. The Schwabach test compares the patient’s level of bone conduction hearing to that of a presumed normal-hearing examiner. The Weber test has been modified by many audiologists for use with electronic equipment. When the test is administered, the patient is askedto tell the examiner the location of the tone heard (left ear, right ear, both ears, or midline) in order to determine whether the hearingloss is conductive, sensorineural, or mixed.
This procedure is contraindicated for
- Evaluate type of hearing loss (conductive or sensorineural)
- Screen for hearing loss as part of a routine physical examination and to determine the need for referral to an audiologist
- Normal air and bone conduction in both ears; no evidence of hearing loss
- Bing test: Pulsating sound that gets louder and softer when the opening to the ear canal is alternately opened and closed (Note: This result, observed in patients with normal hearing, is also observed in patients with sensorineural hearing loss.)
- Rinne test: Longer and louder tone heard by air conduction than by bone conduction (Note: This result, observed in patients with normal hearing, is also observed in patients with sensorineural hearing loss.)
- Schwabach test: Same tone loudness heard equally long by the examiner and the patient
- Weber test: Same tone loudness heard equally in both ears
Abnormal findings related to
- Conduction hearing loss related to or evidenced by:
- Impacted cerumen
- Obstruction of external ear canal (presence of a foreign body)
- Otitis externa (infection in ear canal)
- Otitis media (poor eustachian tube function or infection)
- Otitis media serous (fluid in middle ear due to allergies or a cold)
- Bing test: No change in the loudness of the sound
- Rinne test: Tone louder or detected for a longer time than the air-conducted tone
- Schwabach test: Prolonged duration of tone when compared to that heard by the examiner
- Weber test: Lateralization of tone to one ear, indicating loss of hearing on that side (i.e., tone is heard in the poorer ear)
- Sensorineural hearing loss related to or evidenced by:
- Congenital damage or malformations of the inner ear
- Ménière’s disease
- Ototoxic drugs (aminoglycosides, e.g., gentamicin or tobramycin; salicylates, e.g., aspirin)
- Presbycusis (gradual hearing loss experienced in advancing age)
- Serious infections (meningitis, measles, mumps, other viral, syphilis)
- Trauma to the inner ear (related to exposure to noise in excess of 90 dB or as a result of physical trauma)
- Tumor (e.g., acoustic neuroma, cerebellopontine angle tumor, meningioma)
- Vascular disorders
- Bing test: Pulsating sound that gets louder and softer when the opening to the ear canal is alternately opened and closed
- Rinne test: Tone heard louder by air conduction
- Schwabach test: Shortened duration of tone when compared to that heard by the examiner
- Weber test: Lateralization of tone to one ear indicating loss of hearing on the other side (i.e., tone is heard in the better ear)
Factors that may impair the results of the examination
- Poor technique in striking the tuning fork or incorrect placement can result in inaccurate results.
- Inability of the patient to understand how to identify responses or unwillingness of the patient to cooperate during the test can cause inaccurate results.
- Hearing loss in the examiner can affect results in those tests that utilize hearing comparisons between patient and examiner.
Nursing Implications and Procedure
- Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
- Patient Teaching: Inform the patient this procedure can assist in assessing for hearing loss.
- Obtain a history of the patient’s complaints, including a list of known allergens.
- Obtain a history of the patient’s known or suspected hearing loss, including type and cause; ear conditions with treatment regimens; ear surgery; and other tests and procedures to assess and diagnose auditory deficit.
- Obtain a history of the patient’s symptoms and results of previously performed laboratory tests and diagnostic and surgical procedures.
- Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values).
- Review the procedure with the patient. Address concerns about pain and explain that no discomfort will be experienced during the test. Inform the patient that a health-care provider (HCP) performs the test in a quiet, darkened room, and that to evaluate both ears, the test can take 5 to 10 min.
- Ensure that the external auditory canal is clear of impacted cerumen.
- Note that there are no food, fluid, or medication restrictions unless by medical direction.
- Potential complications: N/A
- Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient.
- Instruct the patient to cooperate fully and to follow directions. Instruct the patient to remain still throughout the procedure because movement produces unreliable results.
- Seat the patient in a quiet environment positioned such that the patient is comfortable and is facing the examiner. A tuning fork of 1,024 Hz is used because it tests within the range of human speech (400 to 5,000 Hz).
- Bing test: Tap the tuning fork handle against the hand to start a light vibration. Hold the handle to the mastoid process behind the ear while alternately opening and closing the ear canal with a finger. Ask the patient to report whether he or she hears a change in loudness or softness in sound. Record the result as a positive Bing if the patient reports a pulsating change in sound. Record as a negative Bing if no change in loudness is detected.
- Rinne test: Tap the tuning fork handle against the hand to start a light vibration. Have the patient mask the ear not being tested by moving a finger in and out of the ear canal of that ear. Hold the base of the vibrating tuning fork with the thumb and forefinger of the dominant hand and place it in contact with the patient’s mastoid process (bone conduction). Ask the patient when the sound is no longer heard. Follow this with placement of the same vibrating tuning fork in front of the ear canal (air conduction) without touching the external part of the ear. Ask the patient which of the two has the loudest or longest tone. Repeat the test in the other ear. Record as Rinne positive if air conduction is heard longer and Rinne negative if bone conduction is heard longer.
- Schwabach test: Tap the tuning fork handle against the hand to start a light vibration. Hold the base of the tuning fork against one side of the patient’s mastoid process and ask if the tone is heard. Have the patient mask the ear not being tested by moving a finger in and out of the ear canal of that ear. The examiner then places the tuning fork against the same side of his or her own mastoid process and listens for the tone. The tuning fork is alternated on the same side between the patient and examiner until the sound is no longer heard, noting whether the sound ceased to be heard by both the patient and the examiner at the same point in time. The procedure is repeated on the other ear. If the patient hears the tone for a longer or shorter time, count and note this in seconds.
- Weber test: Tap the tuning fork handle against the hand to start a light vibration. Hold the base of the vibrating tuning fork with the thumb and forefinger of the dominant hand and place it on the middle of the patient’s forehead or at the vertex of the head. Ask the patient to determine if the sound is heard better and longer on one side than the other. Record as Weber right or left. If sound is heard equally, record as Weber negative.
- Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
- Recognize anxiety related to test results, and be supportive of impaired activity related to hearing loss and perceived loss of independence. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate. As appropriate, instruct the patient in the use, cleaning, and storing of a hearing aid. Educate the patient regarding access to counseling services. Provide contact information, if desired, for the American Speech-Language-Hearing Association (www.asha.org).
- Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. As appropriate, instruct the patient in the use, cleaning, and storing of a hearing aid. Answer any questions or address any concerns voiced by the patient or family.
- Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.
- Related tests include antibiotic drugs, analgesic and antipyretic drugs, audiometry hearing loss, culture bacterial (ear), Gram stain, evoked brain potential studies for hearing loss, otoscopy, and spondee speech reception threshold.
- Refer to the Auditory System table at the end of the book for related tests by body system.