Port Moresby Medical Laboratories (POMMEDLAB)

Audiometry/Hearing Test

Deafness occurs in all ages but more common as we get older. We can walk around without knowing that we have deafness until tested by audiometry. Early diagnosis is very important in children as missed hearing problems can lead to speech problems, learning difficulties in school, behavioral difficulties and disobedience (difficulty child) if not diagnosed early and treated.

 

Individuals working in noisy environments for example industries, airports and workshops with machinery noises all around them are higher risk of hearing loss  if appropriate preventive measured are not taken.

 

How do I know I have hearing problem?

You can not tell if you are deaf in early stages until you are tested. In adult population 1 in 7 suffer from some degree of significant hearing impairment (over 20dB in the better ear). Hearing loss is classed as mild ( soft spoken voice), moderate (normal voice), severe (shout), and profound (deaf).

                 You should have your hearing checked if you:

                 Are deaf

                 Have hearing difficulty

                 Talk very loud in normal environment

                 Work in noisy environment (see occupational audiometry)

                 Hear muffled sounds\

                 Hear ringing &, buzzing sounds

                 Complaint about people mumbling

                 Habit of requesting speech to be repeated all the time

                 Habit of turning radio or TV too high

                 Do not like attending gatherings & parties where lots of noise

                 In children

                 Child often do not follow instructions given

                 Disobedience

                 Learning problems at school

                 Delayed speech or pronunciation problems

                 Behavioral problems (hambak mangi)

                 Unable to pick up direction of sound

                 Recurrent ear infection.

 

How is hearing tested?

At POMMEDLAB hearing is measured using latest specialized computer system called audiometry. We provide both work/occupational audiometry as well as general hearing tests.  The test takes about an hour. No pre-test preparation is required but we advice prior booking for appointment.

The test is performed in a quiet room. You will be given a pair of ear phones to wear and sounds of different frequencies and loudness are generated from the computer and you will press a button every time you can hear the button. This is presented on a audiograph as show below and the pattern generated will determine type or degrees of deafness you may have.

 

What exactly is an audiogram?

Along the horizontal line of the graph the numbers range from 125 to 8000. These numbers refer to frequencies, or different                  pitches of sounds.

 

Frequency is expressed in terms of the number of cycles per second, or Hertz. The higher the number, the higher the pitch of the sound. For example, 250 Hertz (250 Hz) sounds like middle C on the piano, while the high-pitched ringing of the telephone is about 3000 Hz.

Normal, young, healthy human ears can actually hear frequencies as low as 20 Hz and as high as 20,000 Hz, but we only test hearing in the range of 250 Hz to 8000 Hz, as most sounds of speech occur in this frequency range.

Loudness or level of sounds is measured in units called decibels. Zero decibels (0 dB) does not mean ‘no sound’. It is just extremely soft. Conversational voice level is around 65 db, and 120 db is very, very loud—about as loud as a jet taking off when you are standing 25 metres away. The figures along the side of the graph are hearing levels in decibels.

Air conduction thresholds for the right ear (that is, the softest sounds the right ear can hear at each frequency) are marked as an ‘O’, and the left ear is an ‘X’ on the audiogram.

Bone conduction thresholds are marked on the audiogram as ∏ (better ear), [ (right ear) or ] (left ear).

What does the audiogram mean?

Your audiogram is a ‘picture’ of your hearing. It indicates how much your hearing varies from normal and, if there is a hearing loss, where the problem might be located in the hearing pathway. It helps doctors to detect degrees of deafness and whether you have conduction problem (example from wax impaction) or sensorineural deafness (nerve damage) or mixed deafness. The result is reported as:

                 -Mild-loss of 20-40dB (soft voice)

                 -Moderate– loss of 40-70dB (normal voice)

                 -Severe– loss of 70-90dB (shouting)

                 -Profound-loss of over 90dB (completely deaf).

                

Depending on the cause of your deafness you may or may need surgery or hearing aid to have re-establish your hearing.

For example,  middle ear infection is a common cause of a conductive hearing loss in young children. Outer and middle ear blockages can often be corrected by medical or surgical treatment.

 

What other test are available?

While for most, audiometry with examination by your doctor provide bulk of information necessary for diagnosis of your deafness, other laboratory tests available but not provided by POMMEDLAB include tympanometry, speech perception testing and MRI.