IHS Final Study Guide Graded A

IHS Final Study Guide Graded A The fleshy part of the ear that protrudes from the side of the head is called the Auricle or Pinna The average adults canal is about _____ inch in length and about _____ inch in diameter The cone of light is a reflection of the light from The external auditory canal's resonant frequency is an otoscope on the tympanic membrane 1 and ¼ about 2700hz and varies slightly from person to person The structure of the tympanic membrane is made up of 3 layers The transduction of energy as acoustical sound courses through the middle ear which is as follows Acoustical energy is changed into mechanical energy at the tympanic membrane and changed into hydraulic energy at the stapes footplate The promontory is located on the medial wall of the middle ear cochlea Otitis media is an ear infection that may It represents the basal turn of the result from Eustachian tube dysfunction Fluid in the middle ear is also called effusion Otosclerosis immobilizes the ossicles at the stapes footplate The cochlea in located with the petrous portion of the temporal bone. It coils in about Uncoiled it measures about 1 inch Three chambers within the inner ear are called 2 ½ turns. scala vestibuli, scala media, scala tympani The basilar membrane and the reissner's membrane separate the cochlea into three chambers. The organ of Corti is the sensory receptor for hearing The hair cells activate the auditory nerve through electrochemical energy The Place Theory of Hearing is simply explained as the basal turn of the cochlea responds to high frequencies and the apical turn of the cochlea responds to low The singular perception of two different signals presented to each ear simultaneously is fusion An octave is the doubling of a frequency •Masking is define as a procedure used to binaural eliminate the participation of the non test ear while measuring some aspect of auditory function in the test ear The symbol used to document that thresholds were measured with masking presented to the NTE are a blue square for the left ear and a red triangle for the right ear The formula used to determine the initial masking intensity to be delivered to the NTE + 10db The increase in loudness when both ears hear together is binaural summation Sensory/Neural hearing loss is caused by damage or a disorder involving the NTE is AC of hair cells or auditory nerve •Recruitment can result in an exaggerated sensitivity to loud sounds •In ears with cochlear damage, the critical bands are wider than 1/3 octave The impact of sensory/neural hearing loss on critical bands results in: difficulty with speech intelligibility in quiet and noise An audiometric finding that may indicate a retrocochlear disorder is: recognition scores in the presence of symmetrical hearing levels Ototoxic medications result in damage to the organ of Corti asymmetric word A neural disconnection of the auditory centers of the cortex with the rest of the hearing system is known as "central deafness". A tympanometer is used to measure middle ear function For threshold measurement each tone presented should be about Test/retest reliability for threshold measurements is: + 5 db 2 second in duration The hearing instrument specialist must be familiar with the upper limit for threshold determination because it: differs with stimulus (frequency or speech) and with transducer The headband for the bone conduction transducer applies pressure on the oscillator f irmly against the most prominent point on the mastoid The frequency order for BC threshold measurement is holding it 1000 Hz, 2000 Hz, 4000 Hz, retest 1000 Hz, 500 Hz and 250 Hz An air-bone gap is defined as a thresholds of the same ear 15 dB or greater difference between the air and bone conduction Masking is define as a procedure used to eliminate the participation of the non-test ear while measuring some aspect of auditory function in the test ear Plateau refers to the masking intensity