Question

A complete audiometric assessment is comprised of many tests--pure-tone air- and bone-conduction audiometry, speech audiometry (both threshold and suprathreshold determination), otoacoustic emissions, and middle ear analysis (tympanometry, static acoustic compliance, and acoustic reflex threshold). Taken together, these tests provide the most complete diagnostic picture of the peripheral and central auditory systems.

In some cases, however, the audiologist may wish to omit certain tests. Using your knowledge of how each assessment is performed and/or where each audiometric test targets (outer, middle, and/or inner ear, retrocochlear pathway) and the degrees/types of hearing impairment along with how different populations are assessed, when would it be appropriate to omit (a) middle ear analysis and/or (b) otoacoustic emissions?

Please explain in detail at the best of your ability. Please cite websites/resources that are used.

Answer 1

PURE TONE AUDIOMETRY

A pure tone audiometry test finds out the least audible sound a person can hear.The test is performed in such a way that the earphones worn by the patient would be attached to the audiometer.Pure tones are passed to one ear at a time.The patient will be asked to signal on hearing a sound.The minimum volume required to hear each tone is marked graphically.To test bone conduction a device called bone oscillator is placed against the mastoid bone.The sound passed through this device causes the skull to vibrate gently.The vibration goes into the inner ear and comes out through the middle ear and outer ear.

Pure tone audiometry targets outer,inner and middle ear.

SPEECH AUDIOMETRY

In speech audiometry,through a headset  a person's ability to detect and repeat spoken words at different volumes is tested.To test speech recognition threshold, a series of two-syllable words at a volume, that gradually decreases, will be heard by the patient.In the second stage,that is in supra threshold determination, a series of one syllable words at a constant volume(loud enough) will he heard by the patient.

Speech audiometry targets ear drum and middle ear.

OTOACOUSTIC EMISSIONS

Otoacoustic emissions are non invasive measures to detect cochlear functioning.A small earphone is placed in your ear.Sound is passed into your ear and the returned sound is measured.

Otoacoustic emissions targets inner ear or cochlea.

MIDDLE EAR ANALYSIS

Problems in the middle ear makes it hard for sounds to pass through your inner ear and brain.Middle ear analysis include

• Tympanometry
• static acoustic compliance
• acoustic reflex threshold

TYMPANOMETRY is an assessment of the mobility of the eardrum.It tests problems like fluid buildup,perforated eardrum or tumors in the middle ear.ACOUSTIC REFLEX THRESHOLD evaluates the cranial nerves and brain stem.These two tests are performed by placing a soft plug into your ear.The plug will produce a loud noise,change pressure,thus tracking the responses to the sound and various pressures.

STATIC ACOUSTIC COMPLIANCE tests volume of air in the ear canal.

TYPES OF HEARING IMPAIRMENT

• Conductive hearing impairment-It happens when there is a problem with the outer or middle ear,interfering with the passing sound to the inner ear.
• Sensorineural hearing impairment-It occurs when the cochlea or the auditory nerve is damaged and will be unable to send the electrical signal to the brain.
• Mixed hearing impairment-it occurs when both conductive and sensorineural hearing impairment are present.
• TESTS CAN BE OMITTED IF THERE IS INNER EAR DAMAGE