Audiometry

Audiometry is a set of non-invasive diagnostic methods aimed at quantitatively assessing hearing acuity. The procedure allows determining the minimum sound intensity that a person is capable of perceiving at different frequencies.

The result of the examination is an audiogram, a graph that clearly shows the hearing thresholds for each ear. This is the “gold standard” in hearing loss diagnosis, allowing determination of the presence, degree and type of hearing impairment.

Procedure and types

The examination is conducted in a soundproof chamber using a special device called an audiometer. The patient puts on headphones, and the doctor plays sound signals (pure tones) of varying frequency and volume. The patient’s task is to press the button every time they hear a sound.

Main types of audiometry:

• Tonal threshold audiometry. Defines the minimum sound level (hearing threshold) that a person can hear at a standard set of frequencies (usually from 125 to 8000 Hz). Both air conduction (through headphones) and bone conduction (using a bone vibrator applied to the mastoid region) are examined.
• Speech audiometry. Assesses the patient’s ability to perceive and understand speech at different volume levels. This helps determine how much hearing loss affects social communication.

Clinical Significance

Audiometry is a key method in audiology and otorhinolaryngology. Analysis of the audiogram allows the physician not only to confirm the fact of hearing loss, but also to determine its nature.

By comparing the thresholds of air and bone conduction, it is possible to differentiate the type of hearing loss:

• Conductive Hearing Loss. Air conduction is impaired, but bone conduction is normal. Indicates a problem in the outer or middle ear (e.g., earwax blockage, otitis, otosclerosis).
• Sensorineural (neurosensory) hearing loss. Both air and bone conduction are equally reduced. Indicates damage to the inner ear (cochlea) or auditory nerve.
• Mixed hearing loss. Both types of conductivity are reduced, but to varying degrees.

Based on audiometry data, hearing aids are selected, decisions are made regarding the need for surgical treatment or cochlear implantation, and the effectiveness of the therapy being administered is assessed.