Hearing is that sense by which you hear different sounds. Hearing is a complex process and your ears are the main organ that helps in hearing.

Hearing loss is a common type of hearing impairment and occurs when the hair cells in your inner ear (mainly in the cochlea or the hearing organ) are damaged. Hearing loss can be temporary or permanent and is treatable.

Hearing and Its Problems

Your ear consists of the outer ear, the middle ear, and the inner ear. The ear canal located in your outer ear picks sound waves from the environment and passes them to the middle ear. Your middle ear amplifies the sound waves which are converted by the inner ear into electrical signals and sent to your brain for reception.

Your ability to hear allows you to connect and communicate with your surroundings and the world. Hearing impairment can cause discomfort and disturb your routine activities. 

If your doctor suspects a hearing problem, he/she might advise some tests to identify the type of hearing loss. There are many tests that can diagnose hearing loss which may include:

  • Physical examination. Your doctor may examine your external ear for any structural defects and also will look into the inside of your ear for earwax or inflammation, which is causing the hearing loss.

  • Screening tests. Some screening tests like whisper tests, tuning fork tests, and audiometer tests are done to find the exact type of your hearing loss.

Audiometer tests are done by an audiologist (health care professional who is trained to evaluate hearing loss and ear-related disorders). 

The simplest and most common hearing test that is carried out is the Pure Tone Audiometry (PTA). Hence, it is a “gold” standard test of audiological examination.

All About Pure Tone Audiometry (PTA)

During your school days, you would have had your hearing tested in school or at the doctor’s office. You might remember putting on earphones/headphones and raising your hand whenever you heard a “beep” sound. This is pure-tone testing.  

It is also called air conduction testing because the sounds go through your outer and middle ear and it helps to find the quietest sound which you can hear at different frequencies/pitches.

How is PTA Done?

During the pure tone audiometry test, you will be required to wear earphones/headphones and hear sounds and words which would be directed to each ear and each tone will be measured by an instrument called an audiometer, and recorded on the audiogram (a graph that shows the softest sound you can hear at different frequencies/pitch).

Headphones and bone vibrators may be used for testing air conduction and bone conduction respectively. 

Procedure 

  • Pure-tone audiometry test is carried out in a soundproof chamber to elicit an accurate response. 

  • The test would be carried out in a two-room setting where you and your audiologist sit in different rooms. 

  • You will be told to wear a headphone and your audiologist will play the sounds produced by the audiometer and will give you instructions for each sound. 

  • You would be asked to raise your hand or press a button when the sound (e.g., like a “beep”) is heard. 

  • The frequencies are then tested one by one and a graph (audiogram) is plotted which represents the way you hear different sounds, i.e., frequency on the X-axis and volume on the Y-axis in the graph.

  • The shape of the audiogram (graph) gives an indication of the type and degree of your hearing loss.

Type of Hearing Loss

When you undergo a PTA test, the results can tell you about the type of hearing loss which can be: 

  • Conductive Hearing loss. It is when sounds cannot get through the outer and middle ear. You may be unable to hear the soft sounds and louder sounds may be muffled. This condition can be caused due to ear infections, fluid accumulation in the middle ear (due to cold), or perforations of the eardrum. 

  • Sensorineural Hearing loss. Such a type of hearing loss occurs when there is damage to the inner ear or damage to nerve pathways (from the inner ear to the brain). The damage can be due to age, genetics, long-term exposure to loud sounds, etc. In most cases, medication and surgery may not help but hearing aids can help you hear. 

  • Mixed Hearing Loss. When there is damage to the outer or middle ear along with the damage to the inner ear or nerve pathways, it is said that you have mixed types of hearing loss.

Degree of Hearing Loss

The severity of your hearing loss can also be estimated by the graph obtained during PTA. Your doctor will classify your hearing loss on the basis of the intensity of sounds that you can hear. The unit of measurement for sound intensity is the decibel (dB). 

A healthy human ear can hear very low, soft sounds from 0 dB to loud sounds up to 140 dB.

  • Normal hearing (0-15 dB): At this level, hearing is within normal limits. 
  • Minimal hearing loss (16-25 dB): At this level, hearing is usually within normal limits but there is little difficulty in suppressing background noise and occasionally there is a listening effort required.
  • Mild hearing loss (26-40 dB): Mild hearing loss may cause deficient attention span, difficulty in suppressing the background noise, and increased listening efforts. Patients may not be able to hear soft speech. Children may be fatigued after listening for longer periods.                                   
  • Moderate hearing loss (41-55 dB): This may affect language development, articulation problems, interaction with people, hence, lowering the patient’s self-esteem. There is also difficult to hear conversational-level speech.
  • Moderately severe hearing loss (56-70 dB): Moderately severe hearing loss may cause difficulty with speech and difficulty in comprehensibility. Most conversational-level speech cannot be heard in this hearing loss.
  • Severe hearing loss (71-90 dB): Severe hearing loss may affect the quality of the voice.
  • Profound hearing loss (>90 dB): In profound hearing loss (deafness), there is the deterioration of speech and language.            

To summarize, a Pure Tone Audiometry is a reliable and gold standard method to diagnose the type and degree of your hearing loss.


Disclaimer: This article is written by the Practitioner for informational and educational purposes only. The content presented on this page should not be considered as a substitute for medical expertise. Please "DO NOT SELF-MEDICATE" and seek professional help regarding any health conditions or concerns. Practo will not be responsible for any act or omission arising from the interpretation of the content present on this page.