Audiology Flashcards
what is pure tone audiology (PTA)
a hearing test which gives the hearing threshold and what type of hearing loss
what is the first hearing test to be carried out
pure tone audiology
what ranges to audiograms test in
150-8000 decibels
what is the level of normal hearing
hearing all tones up to 20 decibels and quieter
how are left and right represented on an audiogram
X- Left
O - right
(right can never be wrong)
what do brackets mean in an audiogram
that when testing the good ear was masked to prevent it hearing the sound
what is masking
sound to distract the good ear while the bad ear is being tested
what can happen if the good ear is not masked
inaccurate measure of hearing threshold for the bad ear
incorrect diagnosis
inappropriate intervention
difficulty in later interpreting results
what do triangles on an audiogram represent
bone conduction
what does it mean when the brackets and/or triangles sit right on top of the X or O (air and bone hearing the same)
sensorineural hearing loss
what audiogram results are seen in conductive hearing loss
the bone conduction is much better the air conduction
therefor triangles and/or brackets are in a line far above the X and Os
what is sensorineural nearing loss
a result of damage to the hair cells in the cochlea or the hearing nerve
usually occurs as part of the ageing process
what can cause sensorineural hearing loss
- ageing
- regular and prolonged exposure to sound
- ototoxic drugs
- infectious diseases - rubella
- complications at birth
- benign tumours on auditory nerve (schwannoma)
- genetic predisposition
what is conductive hearing loss
hearing loss caused by a blockage to the sound stopping it from reaching the inner ear
what are some causes of conductive hearing loss
sound cant pass through the ear:
ear infections
middle ear fluid (glue ear)
perforated ear drums
treatment for conductive hearing loss
possible to have surgical intervention
what does mixed hearing loss look like on an audiogram
at parts there is a significant gap between air and bone but bone are not all within normal limits
what is mixed hearing loss
a combination of sensorineural and conductive - damage to both the outer or middle and inner ear
causes of mixed hearing loss
genetic factors birth defects diseases infections tumours masses head injuries otosclerosis (which has spread to inner ear)
what is typanometry
a test used to asses the condition of the MIDDLE ear by creating vibrations of pressure within the ear
what does tympanometry allow
distinction between sensorineural and conductive hearing loss to be made
helpful in diagnosing:
otitis media and tympanic membrane perforation
what does otitis media with effusion look like on a tymphogram
presence of fluid in the middle ear reduced the mobility of the tympanic membrane causing a flat line
what does tympanic membrane perforation look like on a tymphogram
shows are large ear canal volume as air escaped through the perforation
(v high peak - off the scale)
what does ossification of the ossicular bones look like on tympanogram
v small curve (does not go very high) positioned more to the right (+ side)
