Hearing Impairments

So what is a hearing impairment?

A hearing impairment is unsurprisingly when a person has difficult hearing. This could be from birth or from a condition that occurs later in life. In general they are catagorised from if it began before or after speech development, as before could heavily impact their language development. As we’ll look at later when talking about speech impairments.

 What are the characteristics of a hearing impairment?

Hearing impairments can either occur in one ear or both and can be diagnosed by being unable to detect sounds in the environment, or the inability for the brain to process the sounds.

The causes of hearing loss are varied and sometimes unknown. Some known causes are prenatal infections, genetics, noise exposure, various diseases and age. Sometimes hearing loss can be corrected with hearing aids, cochlear implants or surgery.

As speech and language may be affect the person may develop skills in sign language (AUSLAN), reading lips and other non-verbal cues. Deaf Culture is also very common with many choosing not to treat their deafness as a disability but rather embrace it through a strong and vibrant community.

What are the range of hearing impairments?

The way in which hearing impairments are categorised are to do with how well they hear on the decibel scale (dB) in the preferred ear.  So if you started at the higher end and decreased the volume at what point would they be unable to hear. The chart below shows some examples of sounds at various decibels.

Decibel Range Chart

Decibel Range Chart

In Australia you are catagorised at profound hearing loss or deafness if you, as an adult, cannot hear at levels less than 91dB. So they may be able to hear a jet or gunshot,  but not a drum. Children are catagorised as having hearing loss if they are having problems with sounds at less than 31dB.

Mild to severe hearing loss is between 25dB and up to 90dB. Normal hearing is classified as being able to hear sounds at less than 20dB, or being able to hear someone whisper.

What is the prevalence of hearing impairments?

Hearing impairments are one of the largest groups with roughly 1 in 6 people in Australia affected by hearing loss, with 30,000 of those with total hearing loss.

As with visual impairments the rates of hearing impairments tend to increase with age, particularly in males who are older than 55, which levels can reach as high as 30-40%. Few children are born with profound hearing loss, approximately 1 in 1000.

How does this impact their computer use?

Provided there is no sound on the site there is not much impact on computer use. Sites which have videos should have closed captions. Videos uploaded to youtube will have some by default, though make sure to proof read for accuracy and update if needed.

Some websites will have sounds to indicate events occurring such as errors, so making sure there is a text equivalent. Some will also play sound or videos by default, FaceBook is currently in the habit of doing this. While this may not bother the user, it may bother the people around them.

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