hearing test

Hearing tests are performed by observing the response caused by acoustic stimulation to understand the state of auditory function and to diagnose the diagnosis of auditory diseases. The purpose is to understand the extent, nature of the hearing loss and the location of the lesion. Patients with hearing loss between 1000 and 4000 Hz of around 40-50 dB are not suitable for cochlear electrograms. The ears are the same on both sides. Basic Information Specialist Category: Otolaryngology Examination Category: Other Inspections Applicable gender: whether men and women apply fasting: not fasting Tips: Not suitable for people: patients with hearing loss between 1000 and 4000 Hz are around 40-50 dB. Normal value 1, the voice test normal whispers can be heard at a distance of 6m. 2. The table test recording method is expressed by the ear listening distance (cm)/the standard listening distance (cm) of the watch, and the small number indicates good hearing. 3. Tuning fork test Normal hearing Linna test air conduction> Bone conduction (+) Weber test The middle Schwabba test is normal (equal). 4. The cochlear electrogram SP does not increase, and the SP/AP ratio is <0.4. 5. The hearing range of normal people is between 0 and 25 decibels (dB). Clinical significance Abnormal results: 1. Voice test The whisper is shortened to 4m, indicating mild deafness, 1m is moderate deafness, and shorter than 1m is severe or complete deafness. 2, the table test recording method is expressed in the ear listening distance (cm) / the standard listening distance (cm) of the watch, the digital number may be bad. 3, the judgment of the tuning fork test results: a Conductive 聋: Linna test air conduction <bone conduction (a) air conduction = bone conduction (+). Weber test: biased to the ear or heavier ears to the ear or lighter ears. Schwabbaine test: extended (+). b sensorineural hearing loss: Linna test air conduction > bone conduction (both shorter than normal) (short +). Weber test: or lighter ears. Schwabbaine test: shortened (+). c mixed 聋: Linna test (+), (-) or (±). Weber test: uncertain. Schwabbaine test: shortened (+). 3 pure tone hearing threshold test: a Conductive tibial curve is normal or close to normal, and the air conduction curve has a hearing loss between 30 and 60 dB. Generally, the low frequency hearing loss is heavier. b The sensorineural hearing loss curve is gradually decreasing or steeply descending, and the high frequency hearing loss is heavier. The bone conduction curve and the air conduction curve are close to each other or coincide with each other. c The mixed patella conduction curve decreases, and the air conduction curve is lower than the bone conduction curve. 4 Listen on the electric reaction side: a. The diagnosis of "-SP" of Meniere's disease is increased, so that the ratio of -SP/AP is greater than the upper limit of the normal range (≥0.4 or =0.45), the SP-AP complex is broadened, and the polarity of SP and AP is opposite. AP is negative and SP is positive. b. Sensory hearing loss SP is difficult to identify, and the CM threshold is significantly improved or the maximum stimulation intensity is still not revealed. The disappearance of CM is an important feature of sensorineural hearing loss. c. Neurological hearing loss AP can disappear, but CM is normal or roughly normal. d. The advantage of auditory neuropathy-SP (SP/AP>0.4), -SP is multi-peak, SP-AP complex waveform is widened, AP amplitude is reduced or disappeared. (SP is the sum potential and AP is the auditory nerve complex potential). Need to check patients with hearing impairment. The result is low, the disease may be high : the noise result is high, and the disease may be: drug deafness, suppurative otitis media, precautions Contraindications before inspection: The sputum in the ear canal should be cleaned up. Taboo when checking: 1. In a quiet environment. 2. During the speech test, the examiner pays attention to the consistency of the pronunciation, the vocabulary is easy to understand, the pronunciation is accurate and clear. Be careful not to let the examinee see the examiner's lips. 3. Select the tuning fork of the appropriate frequency during the tuning fork test. Tap the tuning fork in a certain way. The tuning fork is placed in the correct position during the test. The fork of the tuning fork does not touch the fork, and the fork does not touch the hair. 4. Prevent hearing fatigue. 5. When the watch is tested, the stopwatch should be on the plane of the external auditory canal. 6, the subject should sit well, do not move, and close your eyes. 7, the control ear must be normal, the age of the control should be equivalent. Inspection process 1. Voice test: In a quiet environment longer than 6m, the ground draws a distance mark, the patient stands 6m away from the examiner, but the body can't be too close to the wall to avoid sound interference. The ear to be inspected is facing the examiner, and the other ear is blocked with a cotton ball or finger and closed, so as not to see the examiner's lip movement affecting the accuracy of the examination. The examiner uses the residual air in the airway to emit 1 or 2 syllables first. Vocabulary, 嘱 patients repeatedly say that they hear the vocabulary, should pay attention to the consistency of each pronunciation, the vocabulary is easy to understand, the high and low sounds are used together, the pronunciation is accurate and clear. 2. Table test: the patient sits and closes the eyes, and uses the fingers to plug the non-inspection side ear canal. The examiner stands behind the patient. After familiarizing the patient with the test sound, the stopwatch is placed on the plane of the external auditory canal. The test just heard the distance from the ear to the ear. The recording method is expressed in the ear listening distance (cm) / the standard listening distance (cm) of the watch, such as 100/100 cm, 50/100 cm. 3. Whisper inspection method: carried out in a static room of 6m length. The common vocabulary is spoken in whisper intensity, and the distance that the test ear can hear is recorded and compared with the normal ear (test ear hearing distance/normal ear listening distance). 4. Tuning fork inspection method: The tuning fork is placed about 1cm away from the ear canal, and the listener is "air conduction"; the person who listens to the skull is "bone conduction". It is the most common method for identifying the nature of deafness. Commonly used C octave five sets of tuning forks, the vibration frequency is 128, 256, 512, 1024, and 2048Hz. 5. Pure tone hearing threshold test includes air conduction and bone conduction test: air conduction test starts from 1KHz first, after the patient hears the sound, it descends every 5dB, until it is not heard, then increases the sound intensity by file. (5dB per file), so repeated tests until the exact threshold is detected. Then, in the same way, the hearing thresholds of other frequencies are sequentially tested. Attention should be paid to the use of intermittent sounds to avoid hearing fatigue. The bone conduction test operates in the same way as the air conduction test. 6. Electrical response audiometry: The superposition average technique is used to record the acoustic evoked potentials of the auditory system, to determine the functional status of the auditory system, and to analyze certain diseases of the otology and neurology. At present, there are mainly cochlear electrograms, auditory brainstem responses and mid-latency reactions. 7. Otoacoustic emission examination: Clinically recommended use of transient acoustic evoked otoacoustic emissions (TEOAE) and distorted product otoacoustic emissions (DPOAE) in induced OAE. Inducible otoacoustic emission can be used for neonatal hearing screening, which is simple and rapid. Those who have a positive OAE response can be judged as normal peripheral hearing; combined with auditory evoked potential examination can identify cochlear and post-cochlear auditory system lesions. 8. Acoustic impedance measurement: The basic test items are: tympanic plane static acoustic value measurement, tympanogram and sacral muscle reflex test. Not suitable for the crowd Unsuitable for people: patients with hearing loss between 1000 and 4000 Hz of 40-50 dB are not suitable for cochlear electrograms. The ears are the same on both sides.

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