Classification and Severity of Hearing Impairments

Specific Educational Support Needs: Hearing Impairments

In this work, we approach the Specific Educational Support Needs (SESN) found in some students, focusing specifically on hearing impairments.

Defining Hearing Impairment

Hearing impairment is defined as the loss or abnormality of the function of the auditory system, implying a deficit in the access to oral language.

Students with hearing impairments are those who suffer bilateral hearing losses. Unilateral losses typically allow for normal hearing.

Global Impact of Hearing Loss

According to World Health Organization (WHO) data, there are 32 million children globally with this type of disability. In Spain alone, the number of people with hearing disabilities is close to 1 million.

These data highlight the seriousness of the issue and the necessity of in-depth study regarding support and classification.

Classification of Hearing Impairment

Hearing impairment is typically classified into three main categories:

1. Classification by Onset (Timing)

Based on when the impairment appears relative to language acquisition:

• Pre-lingual deafness: Occurs before the learning of speech.
• Post-lingual deafness: Occurs after the learning process of verbal communication.

2. Classification by Severity (Audiological)

According to the International Bureau of Audiology, hearing loss is categorized by decibel (dB) thresholds:

1. Normal Audition (0–20 dB): The subject can hear a conversation at a medium distance perfectly.
2. Mild Hearing Loss (20–40 dB): In the same conversation, the subject may not understand some words.
3. Moderate Hearing Loss (40–70 dB): The subject needs to be in front of the person speaking to be able to read their lips.
4. Severe Hearing Loss (70–90 dB): The subject will not hear anything in a conversation, but will hear if someone screams.
5. Profound Hearing Loss (more than 90 dB): The subject might only hear extremely loud sounds, such as an explosion.
6. Cophosis or Anacusia: It is the total hearing loss. The subject will not hear anything.

3. Ontological Classification (Location of Injury)

This classification depends on where the injury is found in the auditory system. Its subtypes are the following:

1. Conductive or Transmission Hearing Loss: An alteration in the outer or middle ear. Examples: serious otitis or perforation of the eardrum.
2. Sensorineural or Perceptual Deafness: Occurs when the cochlea is damaged.
3. Central Deafness: Occurs when there is an injury in the central auditory pathways.
4. Mixed Deafness: Involves damage to both the conduction path of sound and its perception.