What are the parameters used to describe an individual's hearing sensitivity?
1. Degree of hearing loss
2. Configuration of hearing loss
3. Type of hearing loss
4. Symmetry of hearing loss
The parameters used to describe an individual's hearing sensitivity depend on the concept of what?
Threshold of hearing
The intensity of a sound at which it can only just be detected: "the minimum effective sound pressure level of an acoustic signal producing an auditory sensation for a specified number of trials"; typically tested at 5 dB intervals to facilitate efficient testing, but sometimes smaller intervals are used.
Threshold of audibility
The total range of frequencies that are audible is approximately _____ Hz to _____ Hz.
20 to 20,000
The normal human auditory system is most sensitive between ______ Hz and ______ Hz.
500 to 5,000
The result of converting the thresholds at the different frequencies into a straight line and labeing it zero dB hearing level
Audiometric zero
As ______________________________ worsens, there is lesser dificulty hearing speech.
degree of hearing loss
This developed a formula that yields a description of hearing loss in terms of percent.
American Academy of Otolaryngology and the American Council of Otolaryngology (AAO/ACO)
True/False: A 50 dB hearing loss is NOT the same as 50% hearing loss.
True
What are the types of configuration of hearing loss?
Flat, sloping, steeply sloping, precipitous, rising, trough or saucer or cookie-bite, notch, corner
"A disorder that involves the structures in the ear that are responsible for conducting sound to the cochlea"
Conductive Hearing Loss
"is involved with both the cochlear function of sensory reception and the functon of the auditory nerve"
Sensorineural Hearing Loss
has "both a conductive component and a sensorineural component"
Mixed Hearing Loss
No "(linkage to any underlying cause or organic pathology)"
Nonorganic Hearing Loss
What are some referral sources?
1. Self-referral
2. Parent or family referral
3. Professional referral
4. Referral following a hearing screening
What questions might an audiologist as about the patient inquiry?
Is there a problem? How serious is the problem? What is the underlying cause or location of the problem? What type of treatment will reduce or overcome the problem?
What types of history need to be discussed when getting a case history?
Hearing history; Medical history; Noise history; Family history; Rehabilitation history
What might we ask about one's hearing history?
difficulty in different listening environments; length of time hearing loss has been noticed; onset sudden or gradual; one or both ears
What might we ask about one's medical history?
history of ear infections; medical or surgical treatment for ear problems; dizziness; tinnitus
What might we ask about one's noise history?
occupational noise exposure; military noise exposure; recreational noise exposure; use of hearing protection
What might we ask about one's family history?
Family history of hearing loss that was not caused by aging or noise exposure
What might we ask about one's rehabilitation history?
previous use of hearing aids; previous use of assistive listening devices
What is the inspection of the ear canal with an otoscope?
The type of audiometer that is desktop design that enables the audiologist to perform many audiological tests. It typically has two channels, one for each ear.
Clinical Audiometer
The type of audiometer that enables having screening in schools, industry, nursing care facilities, etc.
Portable Audiometer
Generates pure tones of different frequencies (octaves and some interoctaves)
Oscillator/Frequency Selector
Allows examiner to select that level of intensity of the tone being presented.
Intensity Dial
True or False: At some frequencies, on all audiometers, maximum possible intensity may be less than at other frequencies.
False- on SOME audiometers
True or False: The most common interval intensity change is 5 dB but most audiometers can be set to change intensity by 2 dB or even 1 dB.
True
Allows the examiner to present the signal to the patient. The length of time this is depressed determines the duration of the tone that is presented to the patient; it can also be set to be in the "on" position
Presentation Switch
Convert energy from one form to another. In an audiometer, these convert electrical signals into sounds.
Output Transducers
What are some examples of transducers?
Loudspeakers; Supra-aura earphones; Insert earphones; Bone oscillators
True or False: Input can be sent to the output transducer from several sources such as the audiometer's oscillator, a CD player, a microphone. It allows the examiner to choose the source.
True
There can be different types of signals sent to the transducer such as __________ and "______________".
noise; warble tones
What is done to ensure that the audiometers' test results are accurate? This is conducted annual so that the audiometer is adjusted to meet American National Standard Institute (ANSI) specifications. It is conducted with equipment such as a sound level meter and "artifical ear."
Audiometer's are "calibrated"also known as calibration
A daily __________ __________ is conducted to verify the operation of the audiometer and check the cords, earphones, etc.
listening check
It is important to test hearing in a ___________ environment. For diagnostic purposes, a sound-treated booth is used (not the same as a sound-proof booth).
quiet
What are the test preparation instructions?
1. Purpose of the test
2. Sit quietly
3. Respond even if the sound is very faint
4. Respond immediately
5. Indicate that each ear is tested seperately
6. Describe behaviors that may interfere with the test
7. Provide an opportunity for questions
What are the types of response options when being tested?
1. Press a response button
2. Raise hand
3. Say "yes"
Why is it important to make sure the earphone is in the right place?
It is important that the earphone be in the proper placement because it is critical to ensure the validity of the results. Patients should remove hats, glasses, earrings, etc. that might interfere with earphone placement. The center of earphone diaphragm should be directly over the opening of the ear canal. Insert earphones should be placed comfortably deep in the ear canal.
How do audiologists familiarize the patient?
By presenting a tone that is at a comfortable, audible level such as 30 dB HL or 50 dB HL.
When the patient responds to a tone, the examiner drops the intensity level down 10 dB and continues to do so until there is no response; After the patient fails to respond to a tone, the examiner increases the intensity of the next tone by 5 dB.
"down 10, up 5" rule
"the lowest decibel hearing level at which responses occur in at least one half of a series of ascending trials, with a minimum of two responses required out of three presentations at single level"; the lowest level is then marked at the appropriate frequency on the audiogram with the appropriate symbol
Threshold
What is utilized to measure the sensitivity of the inner ear? Placement for this is on the mastoid process and the forehead.
Bone conduction testing
"When a sufficiently intense test signal is presented by air conduction testing, it can cross over to the ear not being tested by virtue of bone conducting"; can make it difficult to restrict the test to one ear only since it is sometimes possible for the signal to be heard in the non-test ear
Cross-over effect
To make sure that ONLY the test ear is being tested, ______ is sent to the non-test ear while the test ear is being evaluated.
noise
When do we use masking?
We send masking noise into the non-test ear whenever there is a possibility that the non-test ear can actually hear the sound we are using to evaluate to the test ear.
The amount of reduction in the intensity of a sound as it crosssed through the head from one ear to the other.
Interaural Attenuation
___________ means between the ears;
___________ means reduction
Interaural; Attenuation
The amount of interaural attenuation is different depending on the _____________ we are using.
transducer
Diagnosing the type of hearing loss
Test Interpretation
"the speech recognition threshold is the minimum hearing level for speech at which an individual can recognize 50% of the speech material"; a threshold measure for speech
Speech Recognition threshold (SRT)
The preferred materials to test speech recognition thresholds are ____________ or _____________ ________.
Spondees; spondee words
Compound words with equal stress on each syllable (e.g. hotdog, baseball, airplane, toothbrush) and are similar to each other with respect to audibility
Spondees
True or False: Pure tone test results can be verified if the SRT is compared to the average of pure tone thresholds for 2 or 3 frequencies.
True
The test procedure for obtaining SRTs is using _________ instead of tones. They can be presented by the examiner through a microphone attached to the audiometer so that sound intensity can be controlled, or recorded from a CD or tape and then channeled through the audiometer can be presented.
words
"A measure that requires a patient to respond merely to the audibility of a speech signal rather than identifying a specific word"; "minimum hearing level for speech at which an individual can just discern the presence of a speech material 50% of the time"; measure with any speech signal
Speech Detection Thresholds (SDTs) also called Speech Awareness Threshold (SAT)
Speech Detection Thresholds (SDTs) are sometimes used for evaluation of patients with special needs:
*Non-verbal develomentally disabled adults
*Infants and small children
*Some patients with profound hearing loss
A measure of how well a person understands speech when words are presented at an audible level; previously called "speech discrimination"; different from the other measures we have discussed because the score is a percent correct, NOT A THRESHOLD
Word Recognition Testing
What does phonetically balanced mean?
It means that in a list of 50 words, for example, there is a balance in the use of phonemes with respect to their frequency of occurrence in everyday English.
The most frequently used word list today are the following recorded lists:
*the "W-22" lists
*the NU-6 lists
*The Maryland CNC lists
Sometimes stimuli other than single words in quiet are used to evaluate word recognition. These stimuli include:
*Speech in noise
*Sentences
Words in word recognition testing are usually presented 30 to 40 dB above the patient's speech recognition threshold.
Presentation level
Sometimes words are presented at a level similar to normal conversation levels such as ________________.
50 dB HL
Recorded vs. monitored live-voice presentation
It is preferred that recorded word lists be used
Use of a phrase such as "say the word" or "you will say" before presenting the word tends to result in higher percent correct scores
Carrier phrase
Behavioral information about hearing cannot be obtained from some patients:
*young children
*adults who do not understand the instructions
*adults who are attempting to feign hearing loss
Hearing can be estimated through utilization of _____________ _____________ which measure a physical response from some component of the person's auditory system during or immediately after the presentation of an auditory stimulus. They are not tests of hearing but they measure the responses of elements of the auditory system that are involved in the perception of auditory stimuli; they can serve as a "cross-check" for behavioral measures
Physiologic procedures
"A measurable by-product of auditory system activity- specifically, the outer hair cells in the cochlea-- in response to acoustic stitmulation."
Otoacoustic Emissions
Classification Based on Stimulus Used
*No stimulous:
Spontaneous Otoacoustic Emissions (SOAEs)
Classification Based on Stimulus Used
Click or Tone Burst (Transient):
Transient Evoked Otacoustic Emissions (TEOAEs)
Classification Based on Stimulus Used
Tone Pairs:
Distortion Product Otoacoustic Emissions (DPOAEs)
What are some uses for Otoacoustic Emissions Testing?
*Identification of hearing loss
*Prediction of hearing threshold
*Asseessment of outer hair cells status
*Assessment of processing in the central auditory system
*Differential Diagnosis between cochlear and neural components of hearing loss
*Ototoxicity monitoring
*Noise-induced hearing loss early detection
*Assessment of non-organic hearing loss
The outer, middle, and inner ear convert sound into ________ signals (called _________) that can be understood and processed by the brain.
electrical; potentials
True or False: We can measure the electrical potentials in the brain that occur in response to sound and we can use these measurements for evaluating a patient's auditory system.
True
During this, examiner uses a sound to provoke an electrical response in the nervous system.
Evoked potential audiometry
________________ is the recording of the brain's spontaneous electrical activity over a period of time. Many electrodes are used to record this activity.
Electroencephalography
What are some uses of Auditory Evoked Response Measurments?
*Newborn hearing screening
*Estimation of auditory thresholds
*Assessment of Central auditory system
What type of test is being described? Test of hearing; active participation; patient has to understand the task; simple/inexpensive equipment; subjective data
Behavioral test
What type of test is being described? Test of the physical response of some part of the auditory system; passive cooperation; no understanding of tast required; complicated expensive equipment; objective data, but often requiring subjective interpretation
Physiologic test
Type of test that "assess the function of the outer and middle ears, with implications for the inner ear, auditory nerve, and lower brainstem”; also includes tympanometry and middle ear muscle reflexes (MEMRs)
Acoustic immittance
Immittance is a measure of energy flow whether the measure is ___________ or ___________.
admittance-based or impedance-based
What is admittance-based immittance?
"energy flow into a system"
What is impedance-based immittance?
"opposition of energy flow into a system"
Why do we do acoustic immittance tests?
All the test requires from the patient is that they are relatively quiet, sitting fairly still, and are not swallowing or chewing gum
There can be a middle ear issue without a hearing loss
The results are one more piece of the puzzle to find out where the hearing loss is
The mobility of the TM in response to varying pressure in the ear canal
Static compliance
Measures ear pressure; A function of the mobility of the TM due to varying ear canal pressure; for a normal middle ear, the more negative or positive the pressure becomes, the less compliant (mobile) the TM
Tympanometry
Measures the contraction of the stapedius muscles in the middle ear in response to loud sounds
Acoustic reflex
_____________ makes repeated measures of the mobility of the TM while ear canal pressure changes.
Tympanometer
What are you looking for during tympanometry?
the point where the TM is most compliant (the peak on the tympanogram)
The pressure at where it happens
The magnitude of the peak
"an estimation of the volume that exists between the probe tip and the tympanic membrane”; typically measured at +200 daPa
Equivalent ear canal volume
What are normal volume values in the ear canal?
0.3-0.9 for children (about 0.5 cm3 is normal)
0.5-1.5 for adults
Of the three, __________ _______ has the least diagnostic value “due to overlap of values from normal and pathological ears”
acoustic admittance
“is an indirect estimation of the pressure in the middle ear cavity…”; Could reflect Eustachian tube dysfunction; Normal values: -100 to +50 daPa
Tympanogram peak pressure (TPP)
“a calculation of the width of the tympanogram in the region of its peak; given in daPa”
Tympanometric width
How is tympanometric width calculated?
you divide the compliance by two, and then draw a horizontal line across the tympanogram; the line should intersect the tympanogram at two points and the distance between these two points is the tympanometric width.
Type of tympanogram: Normal peak compliance and pressure
Type A
What are the abnormal Type A subtypes?
Type AD and Type AS
Type of tympanogram: normal middle ear pressure but excessive compliance (greater than 1.7 mmHo)
Type AD
Type of tympanogram: normal middle ear pressure but reduced compliance (less than 0.3 mmHo)
Type AS
Type of tympanogram: no peak at any pressure
Type B
What happens if the volume is normal on a Type B tympanogram?
it indicates that there is fluid behind the tympanic membrane
What happens if the volume is high on a Type B tympanogram?
it indicates that the tympanic membrane is perforated (also measuring the volume of the middle ear cavity)
What happens if the volume is low on a Type B tympanogram?
it indicates possibility of occluded ear canal (i.e. excessive cerumen)
Type of tympanogram: normal compliance, but negative pressure; indicates that the middle ear cavity pressure is too negative; could indicate Eustachian tube dysfunction
Type C
“bilateral contraction of the middle ear muscles, primarily the stapedius muscle, in response to a high-intensity acoustic stimulus (a tone or a band of noise) delivered to one ear.”
Acoustic Reflex
In acoustic reflex testing, we introduce a high-intensity sound into the ear canal and measure any resulting movement of the tympanic membrane. This is called a _______________.
“stapedial reflex” or an “acoustic reflex”.
True or False: When the stapedius muscle contracts, it pulls on the ossicular chain which results in movement of the tympanic membrane. We can measure this movement of the tympanic membrane with immittance measurement and in that way we can detect when a reflex contraction has occurred.
