Hearing Tests

At CQ Hearing, we treat testing hearing very seriously. Our testing facilities and equipment meet or exceed the Australian/New Zealand standards and our Audiologists is a full member of Audiology Australia and an Accredited Audiologist. You are your Doctor can be confident that the results are valid and accurate.

Our test battery includes:

  • Otoscopy – using an ear light to look for any abnormalities
  • Tympanometry – assessment of your middle ear function
  • Pure Tone Audiometry – Air and Bone conduction thresholds
  • Speech Audiometry – a test of your speech perception

We offer two types of hearing tests for Adults. A Baseline audiometry test for $45.00 and a Full Diagnostic Tests for $75.00. At CQ Hearing our baseline tests also includes an assessment of your middle ear function and speech perception. This test is also used for our on-site workplace testing.

To arrange a hearing test, please contact us by email hear@cqhearing.com or by calling 07 4922 4623.

Evaluating Hearing

When we assess a person’s hearing, we are looking to establish firstly, whether a hearing loss exists, and secondly, if there is a loss, what is the extent and the nature of the loss. That is, is the loss mild, moderate or profound and is the loss conductive or sensorineural or mixed.

As part of the hearing test we are looking to identify and record the person’s hearing thresholds. Hearing Thresholds are defined as the lowest (softest) sound level a person can detect the presence of a signal. This may change from frequency to frequency or from ear to ear. The main frequencies tested are 250, 500, 1000, 1500, 2000, 3000, 4000, 6000 and 8000 Hz. This information is plotted onto a graph which is referred to as an audiogram.

Evaluating Hearing

In the above audiogram we have recorded the subject’s air conduction hearing thresholds for the left ear (blue crosses) and for the right ear (red circles). By air conduction we mean the hearing thresholds when sound is delivered into the air in the subjects’ ear canals. Air Conduction (AC) thresholds provide an indication of the subject’s overall hearing levels.

The above audiogram also shows the classification of hearing losses – mild, moderate, severe and profound. For this subject, as all their thresholds are above 20 DbHL, we would conclude that they have “normal hearing”.

While Air Conduction thresholds will indicate the severity of any loss they do not reveal the type of hearing loss. That is whether it Sensorineural, Conductive or Mixed. This is important as this will provide the basis for deciding on what treatment or solutions might be available to the subject.

By completing both Air Conduction thresholds and Bone Conduction thresholds, we can determine the type of hearing loss as well as the severity of the loss. Bone conduction thresholds are recorded by presenting sounds via a bone conductor placed behind the ear.

Evaluating HearingEvaluating Hearing

In the audiogram above left we can see an example of a mild Conductive Hearing Loss. This person would be referred to an ENT for medical intervention. The second audiogram above, is indicative of a mild to moderate Sensorineural Hearing Loss, mostly above 2000 Hz. This person may wish to trial amplification.

Hearing and Hearing Loss

So How Do We Hear?

Outer, Middle & Inner Ear

The ear is made up of 3 parts:

  • Outer Ear
  • Middle Ear
  • Inner Ear

Each of these three parts has a special function that collectively allow us to hear.

Outer Ear

Outer Ear

  • Sound is first picked up by the outer ear or pinna (also known as ‘auricle’) and Directed down the ear canal to the eardrum – tympanic membrane
  • Essentially the pinna acts as funnel directing sound into the hearing system
  • The outer ear also contributes to directionality

Middle Ear

Middle Ear

  • As sound is sent down the ear canal, sound vibrations cause the eardrum (also known as the tympanic membrane to rock back and forth.
  • Three tiny bones (ossicles) in the middle ear form a bridge that conducts the sound vibrations across from the tympanic membrane to the inner ear.
  • As sounds move across this bridge, they are amplified by up to 27 times.
  • The middle ear also includes the Eustachian tube which connects the middle ear to the back of the nose and throat (nasopharynx) and allows drainage of middle ear secretions into the nasopharynx.
  • The Eustachian tube also provides the means by which we equalise air pressure in the middle ear cavity.

Inner Ear

Inner Ear

  • In the inner we have the Cochlea
  • The Cochlea is a snail shell shaped structure which contains over 15,000 tiny hair cells which are arranged in frequency order.
  • Vibrations received from the middle ear cause these hair cells to move producing a neural signal which is sent to the brain via the auditory nerve.
  • In addition to separating sounds, the hair cells also amplifying soft sounds.
  • So the cochlea receives vibrations, mechanical energy, and converts these vibrations into an electrical signal that the brain can make sense of

So How Do We Hear?

Hearing

  • Sound waves enter through the outer ear and ear canal and are collected on the tympanic membrane causing it to vibrate.
  • These vibrations are transferred to the ossicular chain in the middle ear. This transfer has caused sound energy to become mechanical energy.
  • This mechanical energy is transferred to the inner ear via the ossicular chain and is received by the cochlea at the round window. The cochlear transforms mechanical energy into neurological impulses which travel to the brainstem via the auditory nerve.

Hearing Loss

There are two main types of hearing loss – a Conductive Hearing Loss and a Sensorineural Hearing loss

In a Conductive Hearing Loss sound is blocked in the outer or middle ear and it cannot get to the cochlea efficiently.

Causes

  • Damage to the eardrum
  • Infection or fluid in the middle ear
  • Ossicular bones have become dislodged, damaged, or stiffen (otosclerosis) which reduces their capacity to transfer sound from the tympanic membrane to the Inner Ear
  • Excessive earwax (but it must be large thick plug to effect hearing)

Solution

  • Most often treated medically with high success
  • Hearing device will be a successful alternative if unable to treat medically

The other main type of hearing loss is referred to as Sensorineural Hearing Loss (SNHL). Most typically in a SNHL the hair cells in the cochlea have become damaged or deficient. Occasionally a SNHL may be caused by damaged to the auditory nerve. Either way signals been sent to the brain are compromised.

Causes

  • Aging
  • Noise Exposure
  • Hereditary factors
  • Disease
  • Oto-toxic drugs
  • Trauma

Solutions

  • Cannot be corrected with medicine or surgery
  • Hearing aids will provide great benefit’
  • For profound losses cochlea implant

Some folks have both a conductive hearing loss and a sensorineural hearing loss.

This is referred to as a mixed hearing loss.

Solutions

  • Depends on the contribution and nature of each type.
  • Surgery may be possible, but amplification is also likely to be needed to overcome the loss

Hearing

The other main type of hearing loss is referred to as Sensorineural Hearing Loss (SNHL). Most typically in a SNHL the hair cells in the cochlea have become damaged or deficient. Occasionally a SNHL may be caused by damaged to the auditory nerve. Either way signals been sent to the brain are compromised.

Causes

  • Aging
  • Noise Exposure
  • Hereditary factors
  • Disease
  • Oto-toxic drugs
  • Trauma

Solutions

  • Cannot be corrected with medicine or surgery
  • Hearing aids will provide great benefit’
  • For profound losses cochlea implant

Some folks have both a conductive hearing loss and a sensorineural hearing loss. This is referred to as a mixed hearing loss.

Solutions

  • Depends on the contribution and nature of each type.
  • Surgery may be possible, but amplification is also likely to be needed to overcome the loss