The following tests are common in clinical practice: pure tone audiometry, acoustic impedance, stapedius muscle reflex, otoacoustic emission and auditory brainstem response potentials. Pure tone audiometry is a procedure in which the doctor wears a binaural headset in the pure tone audiometry room and gives the patient a pure tone of 2,000-8,000 Hz in both ears to measure the hearing value of a certain frequency. If it is below 25 decibels, it means deafness; if it is above 25 decibels, it is normal hearing. A parabolic curve of acoustic impedance indicates a normal tympanic membrane; if the curve is flat, consider middle ear effusion. Stapedial muscle reflex with a flat curve represents conductive deafness. Otoacoustic emissions and auditory brainstem response potentials, often given to the patient 90 decibels of sound stimulation, if the reflex value is 25 decibels or less, represents the patient binaural reflex delay, consider the neurodeafness.