The audiogram is a graphical display of the hearing test results. The graph indicates the softest sounds the patient can hear at various frequencies. The results will provide ear specific information on the hearing statue of each ear such as the type of hearing loss and the degree of hearing loss.

The Audiogram graph is normalized to normal hearing level with the normal hearing limit between 0 to 25 dB HL. Symbol ‘X’ and ‘O’ are often used to indicate the hearing thresholds for left and right ears respectively. The severity of the hearing impairment is classified as follows:

• Normal: 0 to 25 dB HL
  No significant hearing difficulty
• Mild: 25 to 40 dB HL
  Difficulty with soft speech but manages well with most situations.
• Moderate: 40 to 55 dB HL
  Difficulty understanding speech especially in noisy situations. TV and radio often have to be adjusted louder.
• Moderate to Severe: 55 dB HL to 70 dB HL
  Clarity of speech is significantly affected. Speech need to be louder and may still have difficulty in group conversation and noisy situations.
• Severe: 70 dB HL to 90 dB HL
  Normal conversational speech is inaudible. Speech understanding is still poor even with loud speech.
• Profound: above 90 dB HL
  Speech intelligibility is still poor even with hearing aid amplification. Cochlear implant could be a better alternative.

With the everyday sounds super-imposed onto the audiogram, one can now better understand the impact of various degrees of hearing impairment on individual hearing ability.

From the above diagram, we can see that our daily conversation hovers around 30 to 50 dB. So for someone with an average hearing threshold of 70 dB HL, he or she will have difficulty hearing or participating in the conversations as the bulk of the speech sounds could not be heard. As a result, one has to speak much louder in order for the hearing impaired individual to understand the conversation as far as possible. In a noisy situation such as restaurants, the degree of hearing difficulty increases. Besides speech signal, one can also notice that most of the environmental sounds such as birds chirping sounds will be missed or much reduced in volume.