When reading an audiogram, it is not simply stating the type of loss and then determining the impact. It also covers ______.
the degree and configuration of the hearing loss.
This is another reason hearing loss cannot be specified in terms of percent of loss.
The ____ of hearing loss tells you which part of the auditory system is damaged:
TYPE
Non-Organic
Conductive
Sensorineural
Mixed
The __________ relates to the degree and pattern of the hearing loss: essentially the “shape” of the hearing loss.
CONFIGURATION
Flat
Sloping
Precipitous
The ______ relates to how severe the loss is in terms of db HL (intensity). This scale is a combination of child and adult degree of loss.
DEGREE
Degree of hearing loss is dependent on the ___ of the patient.
age
The _____ the child, the more detrimental the impact a loss will be to speech and language acquisition.
younger
True or False: It is not important to specify the impact of hearing loss at an early age.
False. It is important so different degrees of loss are noted between children and adults.
CHILD and ADULT degree of hearing loss combined Chart;
-10 to 15 =Normal
16 to 25 = Slight
26 to 40 = Mild
41 to 55 = Moderate
56 to 70 = Moderate Severe
71 to 90 = Severe
91+ = Profound
CHILD degree of hearing loss Chart;
15-25 = Slight
26-30 = Mild
31-50 = Moderate
51-70 = Severe
71-120 = Profound
Adult degree of hearing loss Chart;
0-25 = Within Normal Limits
26-40 = Mild
41-55 = Moderate
56-70 = Moderately Severe
71-90 = Severe
91+ = Profound
What is considered Normal Hearing in children?
up to 15db
What is considered Normal Hearing in adults?
Up to 25db
Adults with mild hearing loss (between 26 and 40 dB) may hear reasonably well in __________, but will miss words and speech sounds when speech is quiet or when there is background noise present.
one-on-one conversation
Adults with moderate hearing loss (between 41 and 70 dB) miss a lot of _____ _____ and telephone conversation.
speech sounds
______ hearing loss (between 71 and 90 dB) need hearing aids to perceive speech sounds almost all of the time. People with ______ hearing loss will miss the vast majority of conversational speech and using telephones will be very difficult.
severe
Adults with _______ hearing loss (91 dB or more) cannot hear speech sounds even if they are very loud. People with ______ hearing loss need hearing aids or cochlear implants to perceive speech sounds.
profound
(Speech Audiometry) Testing involves the use of recorded or (MLV) to present words/sentences. What does MLV stand for?
monitored live voice
When testing is carried out in either ear, this is considered _____.
monaural
When testing is carried out in both ears simultaneously , this is considered _____.
binaural
The ______ system allows the audiologist and patient to communicate while the patient is in the audiology suite.
talkback
Patient’s Role
The patient must understand the task, so presentation/understanding of directions is essential.
_______ can range from an oral reply, written reply or the identification of a picture/object.
Responses
____ ______ are possible due to interpretation of the patient’s response or if the patient can visually read the tester’s lips.
False responses
Clinician’s Role
Present the instructions in an intelligible manner to ensure the patient understands the task
Eliminate visual cues when presenting words orally (MLV)
Presentation of the words at a rate that the patient can understand and answer correctly
Obtaining speech thresholds is important because:
Results can be compared to an average for normal hearing individuals
They provide a good cross check to pure tone testing to ensure accuracy of testing
The can aid in acquiring responses for difficult to test patients that may not respond to pure tone testing, especially fakers
Broken into speech recognition threshold (SRT) and speech detection threshold (SDT)
The lowest level, in dB, at which a subject can barely detect the presence of speech and identify it as speech.
SDT = Speech Detection Threshold
Does not imply that speech is in anyway understood – rather that they detect its presence
The patient responds by acknowledging they recognize it as speech
The lowest hearing level at which speech can barely be understood.
SRT = Speech Recognition Threshold
The lowest hearing level at which 50% of a list of spondee words is correctly identified.
A word with 2 syllables, both pronounced with equal stress and effort.
Spondee
On an Audiogram, The SRT is always ______ (requires a _______ intensity) than the SDT.
Higher, Greater
When the SRT is compared to the PTA, they should be within ___ db of each other.
7
This shows us the test reliability through cross checking.
The ____ can also be used to counsel patients regarding the degree of hearing loss.
SRT
SRT may be much better than the PTA when there is a _______ hearing loss.
precipitous
Does cross over exist for SRT tests just as it does for pure tone testing?
Yes, When the test ear, minus the IA (40 dB for supra-aural earphones, 70 dB for inserts), is greater than or equal to the BC thresholds of the nontest ear.
The SRT of the test ear should be compared to the ______ (best) BC threshold of the nontest ear.
lowest; SRT (test ear) – IA (40dB) > best BC (nontest ear)
SRT Masking
Must be used to obtain the true threshold of the test ear without the influence of the nontest ear.
Speech is a ____ band of frequencies, so the masking spectrum must be just as broad.
broad
SRT Masking Uses a broad band noise called _____ noise due to its weighting around the speech frequencies.
speech
MCL stands for ____.
B. Most Comfortable Loudness
Most people with normal hearing find speech most comfortable at ______ above threshold.
40-55 dB
How is the MCL obtained?
By continuous discourse as the patient rates the loudness level.
Indicated by stating if its too soft, too loud or most comfortable.
UCL stands for ____.
Uncomfortable Loudness Level
____ _____ individuals usually extend to the upper limits of the audiometer (100 to 110 dB HL). Hearing disordered/Normal hearing?
Normal hearing
Some patients with hearing disorders have a much _____ UCL.
lower;
The Range of Comfortable Loudness (RCL) is the arithmetic difference between the ____ and the ____.
SRT and the UCL.
The difference (RCL) is also called the ______.
Dynamic Range for Speech
The dynamic range is much _____ for a normal hearing individual than for a person with a hearing impairment.
larger
Word Recognition Scores
A word list is presented to the patient and they are asked to repeat what they hear.
Their answers are recorded and scored as a percentage for comparison.
Validity of the speech recognition test:
How well it measures what it is supposed to measure (difficulty understanding speech).
How it compares with similar measures.
How the test stands up to alterations of the signal (distortion or noise).
Quantitative results help:
Determine the extent of speech recognition difficulty
In diagnosis of the site of the disorder
Aid in the selection of amplification
Aid in the prognosis for the outcome of treatment
The more _____ and the more acoustic _______ in a word, the more easily it's recognized.
phonemes,redundancy
_____ ______ gets poorer as more and more high frequencies are eliminated from speech.
Word recognition
As more and more high frequencies are eliminated from speech the overall loudness is not effected very much, but what happens to intelligibility?
Intelligibility decreases.
As frequencies below about 1900 Hz are removed from speech, the effect on discrimination is much ___ than when higher frequencies are removed.
less
The difference in intensity between the signal and the noise is called the _____.
Signal-to-noise-ratio (SNR)
_______ ________ is a term used as an all-encompassing term to describe measurements made of TM impedance, compliance or admittance.
Acoustic immittance:
Not impedance “audiometry” because we are not measuring their hearing sensitivity
Not middle ear measurements because they are made at the plane of the TM
_____ ______ is the total opposition to the flow of acoustic energy (in the plane of the TM).
Acoustic Impedance
Consists of mass reactance, stiffness reactance and frictional resistance and is influenced by frequency.
Acoustic Impedance
Most devices measure _______, which is related to the dimensions of an enclosed volume of air as expressed by different units of measurement.
compliance;
Cubic centimeters (cm3) or milliliters (ml)
Compliance is the inverse of _________.
stiffness
What are the 3 measurements at the plane of the TM?
Static Acoustic Compliance/Admittance
Tympanometry
Acoustic Reflex
The mobility of the TM in response to a given value of air pressure in the external ear canal:
Static Acoustic Compliance/Admittance
Essentially measuring the mobility of the TM
A measurement of middle-ear pressure, determined by the mobility of the TM as a function of positive/negative pressure in the external ear canal:
Tympanometry
The more positive/negative the pressure is, the less mobile the middle-ear becomes
Measurement of the contraction of the middle ear muscle (stapedius muscle) in response to intense sounds:
Acoustic Reflex
Stiffens the middle-ear system by contracting and decreases its static acoustic compliance
_______ is determined by frictional resistance (R), mass (M) and stiffness (S).
Impedance (Z)
The effects of mass and stiffness are critically dependent on the _______ of the sound being measured.
Frequency (f)
Complex Resistance(opposition of force)/Reactance (total acoustic impedance provided by mass, stiffness and frequency):
is the combination of the mass and stiffness resistance/reactance
T or F: Mass reactance and stiffness reactance are inversely related to each other.
True
As frequency _______ , the total value of mass reactance factor also increases.
increases
________ is important for high frequencies.
Mass
________ is important for the low frequencies.
Stiffness
As stiffness ______, compliance decreases.
increases; causing (decreased motion)
___________ is determined primarily by the ligaments that support the ossicles.
Resistance (opposition to a force)
_____ factor is determined primarily by the weight of these 3 tiny bones and the TM.
Mass
_____ is primarily determined by the load of fluid pressure from the inner ear on the base of the stapes.
Stiffness
The ear is a largely _______-dominated system, at least for the low frequency response.
stiffness
Conductive losses usually have the greatest effect on the _____ frequencies in the initial and medial stages.
lower
Middle ear pathology ______ the middle-ear system (decreases compliance).
stiffens
Stiffness is _________ as the frequency increases (gets higher).
lessened
3 primary components of an electroacoustic immittance meter:
Speaker
Microphone
Air-pressure pump
These 3 primary components of an electroacoustic immittance meter must be calibrated so that O daPa (or O mm H2O, or O ml) is equal to the atmospheric pressure at the site where measurements are to be made. Why is this?
Changes in altitude vary from place to place and cause changes in atmospheric pressure.
Which of the 3 primary components of an electroacoustic immittance meter emits a pure tone, usually 220 or 226 Hz?
Speaker
High frequency pure tone at ______ is used for children 6 months and younger.
1000 Hz
Cannot use _____ probe tone on babies!!!!!
226 Hz
Which of the 3 primary components of an electroacoustic immittance meter picks up the sound in the external ear canal (to and from TM)?
Microphone
Which of the 3 primary components of an electroacoustic immittance meter creates either positive or negative air pressure within the canal?
Air-pressure pump
T or F: It is acceptable for some debris or cerumen to be in the ear canal during testing.
False. Any small amounts can cause an occlusion of one of the probe tubes and alter test results.
When the probe tip is pressed into the ear canal does the seal have to be tight?
Yes. A tight seal MUST be obtained.
When a tight seal is obtained, Positive pressure is ____ with the air pump.
increased
The first measurement is referred to as C1 or the equivalent ear canal volume:
Made by immobilizing the TM due to positive air pressure
Primarily represents the compliance of the outer ear
The second measurement is C2, or static acoustic compliance (when pressure is gradually decreased until the TM achieves maximum compliance);
Represents the static acoustic compliance of the outer and middle ear combined
Research does not agree on a set values that constitute normal static acoustic compliance:
Differences exist between adults and children and between the various probe tone frequencies
Values cannot be considered abnormal unless one of the extremes is clearly exceeded
Even normal middle ears values vary with age and gender
_______ values below the normal range suggest some change in the stiffness, mass or resistance of the middle ear.
Compliance
Changes in the stiffness, mass or resistance of the middle ear causes reduced (abnormal) mobility of the TM;
Results from fluid accumulation in the middle ear space
Immobility of the ossicular chain
Reduced elasticity of the TM may be due to age or previous healing of perforations
High compliance comes from disruption of the ossicular chain (disease/fracture), or abnormal elasticity of the TM
On page 171 of your Martin text, a chart shows the general tymp norms. The 3 measurements include:
Y (mmho or cm3)
TPP/TW (daPa)
Vea (cm3)
The measurement that shows essentially how high/low the peak is on the vertical plane (compliance)is the ________.
Y (mmho)
The measurement that shows essentially where the peak of the tymp is located (TPP) on the horizontal plane is the ____________.
TW/TPP (daPa)
When referring to Gradient or GR (TW) it is measuring the width of the tymp
The measurement that shows equivalent ear canal volume is the ________.
Vea (cm3)
_________ is the measurement of middle-ear pressure, determined by the mobility of the membrane as a function of various amounts of positive and negative pressure in the external ear canal (Martin, 2009).
Tympanometry
More pressure = (more or less) mobility of middle-ear system.
less
The purpose of tympanometry is:
to determine the point and magnitude of greatest compliance of the TM.
The probe tip introduces air pressure equal to _____ daPa, measures its compliance and then re-measures compliance as the pressure is released.
+200
For adults, tympanometry is conducted with a low-frequency probe tone of ___ Hz.
226
For children 6 months and younger, a ____Hz probe tone is used.
1000
________ is a diagram that shows compliance on the y-axis (vertical) and pressure in dekapascals (daPa) on the x-axis (horizontal).
Tympanogram
Tympanogram Type A:
normal middle ear function; greatest compliance at O daPa.
Tympanogram Type As:
peak at or near O daPa, suggesting normal middle ear pressure, but the peak is shallower than a Type A.
Stapes may have become immobilized. (stiffness/shallow)
Tympanogram Type Ad:
may look like a Type A, but the amplitude of the curve is unusually high or the sides may not meet at all.
Flaccidity of TM or separation of ossicular chain. (discontinuous/ deep)
Tympanogram Type C:
when the pressure falls below normal. TM most compliant when pressure in the canal is negative.
Excessive negative pressure may have an absent peak on screen and become confused for a Type B tymp.
Tympanogram Type B:
middle ear space filled with fluid. Pressure introduced from probe cannot match the pressure of the fluid behind the TM.
Cannot find the point of greatest compliance.
Also occurs when the probe is occluded with debris/ear wax.
TM perforation also.
Positive pressures may be observed above ____ daPa.
+50
Positive pressures observed above +50 daPa can result in the following:
Usually seen in children who have been crying and patients who have blown their nose.
Usually resolves after a short time, but if it does not, a medical referral is warranted.
Using different probe tone frequencies and even multifrequency testing can yield different results
According to ASHA’s Board of Ethics (ASHA 2004), SLPs may screen for _______ ear pathology for the purpose of referral for further evaluation and management.
middle
Normal tympanograms accompanied by a present acoustic reflex indicate normal _____ ear function.
middle
________ is contraction of one or both of the middle ear muscles in response to an intense sound.
Acoustic Reflex
With Acoustic Reflex what two muscles are involved?
tensor tympani and stapedius muscle
The role of the tensor tympani is ______.
A little uncertain.
The role of the stapedius muscle is ______.
contracts reflexively in response to intense sound.
This causes the TM to stiffen
Most normal hearing individuals will demonstrate _______ reflexes at 85-100 dB SPL.
bilateral
________ is the signal used to elicit the acoustic reflex.
Reflex-Activating Stimulus
________ is when the acoustic reflex stimulus is presented to one ear and a decrease in TM compliance is detected in the same ear.
Ipsilateral Reflex
________ is when the measurement is made in the opposite ear to the original stimulus.
Contralateral Reflex
The _______ method is used to elicit a response (down 10, up 5 dB).
bracketing
The Upper limits for an Acoustic Reflex should not exceed ____ dB.
115
For no explainable reason, many normal hearing individuals show no acoustic reflex at ____ Hz.
4000
______ is the lowest level at which an acoustic reflex can be obtained.
Acoustic Reflex Threshold
Patients need to be completely silent during the acoustic reflex measurement. This is because:
Vocalizations can be picked up by the microphone
Variations may occur when a patient is breathing heavily
Very sensitive mics may pick up a pulse from blood vessels near the external ear canal
_______ is the path of the acoustic reflex as it ascends from the outer ear to the brainstem and then descends via the facial nerves on both sides of the head to innervate the stapedial muscles in both middle ears.
Acoustic Reflex Arc
Review Slides 37-39 from Ch.6 part 1.
Sound is passed through the middle ear as _____ energy.
mechanical
Sound is then transduced as electrochemical signal in the ______.
cochlea
Sound is finally conducted along the ______ cranial nerve.
VIIIth, Auditory Nerve.
Then to the brain stem
Then to the superior olivary complex
Impulses are also sent to the ______ cranial nerve on the same side of the head.
VIIth, Facial nerve
Almost simultaneously, neural impulses cross the brain stem to the _______ _______ superior olivary complex.
opposite (contralateral)
Neural impulses then sends impulses by that facial nerve to the middle ear on the other side to evoke the _______ reflex.
contralateral
What are the implications of the Acoustic Reflex?
This shows that a stimulus presented to one ear evokes an acoustic reflex in both ears simultaneously
In regards to the implications of Acoustic Reflexes, there are 4 Possible Outcomes of testing:
Reflex present at normal sensation level (about 85 dB SL).
Reflex is absent at the limit of the reflex activating system (usually 110-125 dB HL).
Present, in the case of a hearing loss, but at a low sensation level (less than 60 dB above audiometric threshold).
Present, but at a high sensation level (greater than 100 dB above audio threshold).
Abnormal tympanograms will usually affect the outcome of _____ _____ _____.
acoustic reflex testing
It is important to be aware of the presence of possible ____ ear pathology before testing for the reflex.
middle
Damage to the ______ will sometimes cause the reflex to be absent, depending on the severity.
cochlea (SNHL)
Abnormalities of the _____/____ will also inhibit the reflex response.
nerves/brainstem
Reflexes can also serve as an important cross check for difficult to test patients.
Although you cannot directly predict audiometric thresholds from acoustic reflex testing, it helps to categorize the patient as either having normal hearing or greater than 30 dB SNHL.
True or False: ABRs and OAEs require a behavioral response from the patient.
False
True or False: ABRs and OAEs take the place of pure tone audiometry.
False. A full battery of testing is required for a correct diagnosis.
What are the two classes of OAEs?
Spontaneous and Evoked
True or False: A normal functioning cochlea is capable of producing sounds in the absence of external stimulation.
True. These are called spontaneous otoacoustic emissions (SOAEs)
Spontaneous otoacoustic emissions (SOAEs)occur in over (what fraction) of people with normal hearing?
1/2
What is the range in frequency and amplitude for Spontaneous Otoacoustic Emissions?
They range in frequency from 1000-3000 Hz
They range in amplitude from -10 and +10 dB SPL
Evoked Otoacoustic Emissions (EOAEs)
Occur during or immediately following acoustic stimulation
Help differentiate a sensory versus neural hearing loss, hearing screenings for infants/difficult to test patients, can assess outer hair cell function for ototoxicity or noise exposure
Evoked Otoacoustic Emissions (EOAEs): Two types:
Distortion Product OAE (DPOAE)
Transient Evoked OAEs (TEOAE)
True or False: Must have a normal conductive pathway to acquire EOAEs.
True
Transient-Evoked Otoacoustic Emissions (TEOAEs)
Produced by brief acoustic stimuli such as clicks or tone pips
Responses should be present in nearly all individuals with normal outer, middle and inner ears
Responses should be present for cochlear hearing losses up to 40 dB
Transient-Evoked Otoacoustic Emissions (TEOAEs)
Click stimuli stimulate a wide area of the cochlea and a broad range of frequencies
Present responses to clicks infer that the pathway up to the cochlea (auditory periphery) is unimpaired
A normal, present TEOAE does NOT guarantee normal hearing.
Why???? There may still be lesions/loss past the cochlea.
Transient-Evoked Otoacoustic Emissions (TEOAEs)
An absent TEOAE indicates a hearing loss is present
This does NOT differentiate between a conductive or sensorineural hearing loss
Distortion Product Otoacoustic Emissions (DPOAEs)
When 2 “primary tones” that vary in frequency by several hundred Hz (F1 and F2) are presented to the ear, the normal cochlea responds by producing energy at additional frequencies
Distortion Product Otoacoustic Emissions (DPOAEs)
Varying the frequencies stimulates different areas of the cochlea
Responses often compare favorably with voluntary audiometric results, as long as a loss does not exceed 40 to 50 dB
How are TEOAEs and DPOAEs measured?
A probe is placed in the external canal
A miniature loudspeaker presents the stimulus
A tiny mic picks up the emission and converts it from a sound into an electrical signal
DPOAE and TEOAE have different probe tips that are used due to the difference in stimuli that elicit a response
___ average out background noise and require fewer stimulus presentations than ____.
DPOAEs, TEOAEs
The noise that is averaged out is primarily from the noise in the patients ear
This is why the patient needs to be as quiet as possible due to the inability of the mic to differentiate the noise from the signal.
Present _____ represent an intact cochlea and a clear conductive pathway.
OAEs
Present OAEs also suggest that the stimulated frequency regions of the cochlear are normal or have no worse than a ____ hearing loss.
Mild
If OAEs are present in SNHL, then outer-hair-cell function is intact and location of the disorder is thought to be past the cochlea, which is called _______.
retrocochlear
Transmission from the inner ear to brain involves the conversion of sound into a series of _______ events.
neuroelectric
These measurements establish an objective measure of hearing sensitivity in infants and other persons who are unable to participate in behavioral audiometric tests.
Auditory Evoked Potentials
When a sound is heard, causing a change in ongoing electrical activity of the brain by recording the responses from the scalp using surface electrodes.
Auditory Evoked Potentials (AEPs)
Auditory Evoked Potentials (AEPs):
Sound stimulation in the outer ear stimulates the cochlea
Through the auditory nerve, connections occur to the brainstem and higher centers for audition in the cerebral cortex
The connections occur via nuclei in the central nervous system
Auditory-Evoked Potentials
When the cochlea is stimulated the electrical responses take time to travel throughout the auditory pathway
Due to the time differences, responses can be recorded at each subsequent nucleus in the auditory pathway
_____ is the term used to describe the time that elapses between the initial stimuli and the occurrence of the response.
A. Slowness
B. Amplitude
C. Latency
C. Latency
______ is the strength or magnitude of the AEP.
Amplitude
The early AEPs that occur in the first 10 to 15 milliseconds after the signal introduction.
Auditory Brain-stem Response (ABR): Believed to originate from the VIIIth Cranial Nerve (auditory nerve) and brain stem.
An AEP occurring from 15 to 60 milliseconds in latency.
Auditory Middle Latency Response (AMLR): Originates in the cortex
AEPs that occur between 50 to 200 milliseconds.
Auditory Late Response (ALR) or cortical auditory-evoked potentials: Presumably arise in the cortex
Contingent on some auditory event occurring within a particular context of sound sequence and involve association areas of the brain.
Auditory Event-Related Potentials (ERP) or P300
_____ are a series of electrical events that can have measurements taken along the auditory pathway from the scalp. A. AEPs B. BEPs C. CEPS
A. AEPs
An instrument designed to pick up and amplify electrical activity, which originates in the brain, by electrodes placed on the scalp.
Electroencephalograph (EEG): Waveforms may be observed that aid in the diagnosis of auditory pathologies
Auditory Evoked Potentials/ EEG
To measure an AEP, a series of auditory stimuli is presented to the subject at a constant rate by a transducer (usually insert earphones)
The EEG equipment picks up the neural response, amplifies it and stores the information in a series of computer memory bins
The computer must average out the neural response, along with electrical potentials from muscles (myogenic potentials)
Defined as the procedure for measuring electrical responses from the cochlea of the inner ear.
Electrocochleography (ECoG) or ECochG
Electrocochleography (ECoG)
Electrodes may be placed surgically on the promontory (medial wall of the middle ear)
Requires anesthesia and the presence of a physician
Electrodes may also be placed in the outer ear canal
The further away the electrode is from the cochlea, the smaller the amplitude of the response
Electrocochleography (ECoG)
The focus of this testing has shifted from determining auditory sensitivity to neuro-otological application
Monitoring the function of the cochlea during a surgical procedure
Enhances the results of electrophysiological tests
Assists in the diagnosis and monitoring of inner ear conditions (ex: Meniere’s disease)
Electrodes are placed on the mastoid process, the vertex (top of the skull), and a ground electrode placed on the opposite mastoid, the forehead or the neck. This procedure is called...
ABR Audiometry
ABR Audiometry
Tone pips/bursts provide some frequency specific information
Clicks may also be used to stimulate a response
ABR Waveforms
Seven small waves generally appear in the first 10 milliseconds after signal presentation
Wave I: 8th Cranial Nerve
Wave II: 8th Cranial Nerve
Wave III: Superior olivary complex
Wave IV: Pons, lateral lemniscus
Wave V: Midbrain, lateral lemniscus and inferior colliculus
Wave VI/VII: Undetermined
ABR Audiometry Testing Procedure:
The patient is seated in a comfortable chair
The skin areas for electrodes are cleansed
The electrodes are taped into place
The electrical impedance is checked at the electrode sites
Insert earphones are placed into the ear
The lights are dimmed and the patients is asked to relax
The ABR is still present during sleep.
ABR Audiometry Testing Procedure:
A series of 1000 to 2000 clicks/tone bursts may be presented to elicit a response
Specific click rates must be used to differentiate the response from myogenic/background noise
The stimuli elicit a response from the various nuclei and their responses show up on a graph as a waveform.
If the responses are not present at the initial 70 dB nHL, the intensity is increased by 20 dB.
ABR results will indicate:
1. Absolute latencies of Waves I-V at different intensities
2. Interpeak latency intervals (I to V, I to III, etc.)
3. Wave amplitudes
4. Threshold of Wave V for threshold estimation
5. Comparative response with a higher click rate if used for neurological assessment
True or False: An Auditory Brain-Stem Response may be used as a test for audiological or neurological.
True
For behavioral thresholds, as signal intensity _______ the wave amplitudes become smaller and latencies increase.
decreases
Wave _ usually has the largest amplitude, so the threshold is considered to be the lowest intensity that will elicit a this type of wave response.
Wave V
ABR thresholds are usually within ____ dB of behavioral thresholds.
10-20
Auditory Brain-Stem Response Interpretation:
May also be used as a neurological screening for the central auditory pathway
Pathology usually increases the timing of one or more peaks in the response (indicative of a slowed auditory response)
May be due to a tumor, lesions, abnormalities of the central nervous system (ex: multiple sclerosis)
An abnormal neurologically significant ABR occurs when:
Interpeak intervals are prolonged
Wave latency is significantly different between ears
Amplitude ratios are abnormal (Wave V is usually largest)
Wave V is abnormally prolonged or disappears with high click rate stimulation
Auditory Steady State Response
Another form of auditory-evoked potentials
Useful in frequency specific threshold predictions for kids and can be acquired in an efficient time frame when behavioral thresholds cannot be obtained
Does not require patient consciousness
Can also be used in the soundfield for estimations of hearing thresholds with and without hearing aids
_____ is a continuous “steady-state” neural response whose waveform follows the amplitude-modulated waveform of the ongoing stimulus.
Auditory Steady State Response, ASSR
Auditory Steady State Response (ASSR:
Assumes that if the brain can detect the modulations of the stimulus, it has detected the stimulus itself.
It also eliminates clinician interpretation of results, unlike the ABR.
Hall reports the ABR and ASSR are not ________, but ________ for pediatric assessment.
competitive,complementary
The ___ is better in differentiation of the types of auditory dysfunction.
ABR
The ____ is better at estimation of hearing for moderate to profound sensory/neural hearing loss
ASSR
What is a disadvantage with the ASSR?
The ASSR may overestimate hearing levels for those with normal hearing.
ABR, ECoG and the use of other electrodes provide monitoring of responses from the inner ear/brain during delicate neurosurgical procedures, which is called...
Intraoperative Monitoring
Intraoperative Monitoring
Surgeons often require reports on the condition of the patient, so they may be alerted to possible damage of the auditory system before it occurs.
Surgery on the auditory and facial nerves, as well as the inner ear may benefit from this monitoring.
Pediatric Audiology: Auditory Responses
Children will respond to various types of stimuli better at different age levels
They will usually not respond at hearing threshold, but at a minimum response level
Small children usually respond at a level that may be well above their threshold
Responses vary from voluntary acknowledgment of a signal to involuntary movement of the body: What are some examples?
Head turn, eye blink, startle response, crying, etc.
Auditory Responses are sometimes left to the clinician’s interpretation:
A trained clinician will be able to discern normal body movements from responses when dealing with small children
Working with children requires frequent modification of testing procedures
Infants under 3 Months of Age
Hearing loss interferes with the natural acquisition of speech and language by interrupting the imitative process.
Remember that hearing is a ___ order event.
1st
True or False: A hearing loss will affect the acquisition of skills necessary to acquire spoken language, reading/writing and other academic skills.
True
Hearing loss in infants is often undetected due to lack of _______.
parent follow-up
Babbling occurs for hearing and hearing impaired infants up to _ months of age.
6
After 6 months of age, children with impaired auditory feedback gradually ______ their vocalizations. This is referred to as the ______.
decrease, Auditory Feedback Loop.
The purpose of _____ programs is to identify children with hearing loss before the age of 3 months.
Early Hearing Detection & Intervention (EHDI)
Criteria necessary for a justified screening program:
1. Sufficient prevalence of the disorder
2. Evidence of early detection due to screenings
3. Availability of follow-up diagnostics
4. Treatment accessibility following diagnosis
5. Documented advantage of early identification
Developed as a system for evaluating newborns
Apgar Test (Dr. Virginia Apgar)
The Apgar Test assigns values of 1-10 at 1, 5, and 10 minutes after birth regarding the following:
(A)ppearance
(P)ulse
(G)rimace
(A)ctivity
(R)espiration
Children with low Apgar scores should also be suspected of having a ____.
B. SNHL
Early detection of hearing loss may also aid in the detection of other disorders:
Sudden Infant Death Syndrome (SIDS)
Possibly due to enzymes like BIOTIN
NBS is in the process of approval for screening for biotinidase deficiency
This may also help prevent disorders of the heart, eye, and musculoskeletal system, as well as predisposition to infection.
True or False: Proper training in infant screening is necessary for identification and also counseling of parents.
True
Children with normal hearing may refer on the screening, so it is important to know how to relay the information the parents. Why is this?
Because you don't want to traumatize the parents!
Joint Committee on Infant Hearing (JCIH)
Created a high-risk registry containing a list of indicators of hearing loss (Table 7.2)
Universal Newborn Hearing Screening (UNHS)
Was used instead of the high risk registry, but now accompanies the screening process.
Use of the risk registry only was INVALID due to the recessive nature of many ______ hearing losses.
hereditary
T or F: Cost effectiveness of Newborn Hearing Screening is validated due to the amount of money it would cost for the rehabilitation of late identified children with hearing loss.
True
Neonatal ABR Screening: AABR
The ABR is the “gold star” of screening, but still has some disadvantages such as lack of frequency specific information, dependence on chronological ages and proper training/placement of electrodes.
Automated systems have decreased the need for tester interpretation of results.
Assumed that infants whose ears produce evoked emissions have normal _______ hearing, or no worse than a 30 dB hearing loss.
peripheral
Neonatal OAE Screening
Presence of even a slight conductive loss eliminates measurable emissions.
Only tests to the outer hair cells of the cochlea.
A lesion past the cochlea (retrocochlear) will still produce OAEs with a normal cochlea.
A failed screening OAE shows outer hair cell damage or a possible conductive loss.
_________________ is missed during OAE only screening.
Auditory Neuropathy/dys-synchrony (AN/AD)
OAEs test the outer hair cells, but do not reveal how the brain responds.
Patients with AN/AD have no ____, no acoustic reflexes and normal ___s.
ABR,OAE
Normal OAEs can be seen in some patients whose behavioral audiograms imply ____ _____.
total deafness
The purpose of early identification is to provide the greatest opportunity possible for ________ success.
educational
EHDI programs comprise 3 components:
Birth admission hearing screening
Follow-up diagnostic evaluations for referrals
Implementing intervention before 6 months of age
Objective Testing in Pediatrics:
Referrals may come directly from a hospital screening or due to parental, caregiver or pediatrician concerns regarding auditory development
Pre-test observations should include:
Child’s relationship with caregiver
Their gait
Standing positions
General motor performance
Methods of communication
Table 7.3 & 7.4
Present OAEs show hearing is no worse than the level of a ____ hearing loss.
mild
Tympanometry can also be used to determine:
Abnormal middle ear pressure
Eustachian tube dysfunction
Presence of fluid
Ossicle mobility
Perforated TM
Patency of PE tubes
Presence of ____ and normal acoustic immittance findings rule out middle ear pathology (conductive component) and anything worse than a mild hearing loss before pure tone testing even begins!
OAEs
In Pediatric Testing, what is over half the battle?
Obtaining test results on children is over half the battle.
An experienced team of clinicians can often work so efficiently that children are distracted and tested before they have time to object
At _ year(s) of age, the child with hearing loss may begin to lose the potential for normal spoken language development.
1
This is why screening and early intervention are so crucial
A child with normal hearing sensitivity is acquiring auditory information with the visual input they are receiving to increase ______ learning.
imitative
Behavioral Tests: Birth – 2 years:
When testing younger children, it is noted that a broader frequency range will catch their attention sooner.
The danger of using a broad frequency range stimulus is that children with hearing loss may have normal hearing sensitivity in some frequency regions.
Ex: A precipitous, profound SNHL.
Behavioral Observation Audiometry (BOA):
Used during the first 6 to 8 months of age.
Uses 2 clinicians to direct and test the child.
Observe the eye and head movements of children when responding to sound.
Use of noise makers or toys may be used that are not calibrated.
This works on the child’s recognition, but does little to specify the configuration of the hearing loss due to lack of instrument calibration.
Sound Field Audiometry
The child is placed in the sound suite and 2 calibrated speakers are used for testing
Child responses may vary from eye movement, head turning, change in facial expression, crying, etc.
The use of BOA in the sound field is advantageous due to the calibration of the sound source
The use of voice, pure-tones and noise are used to obtain responses
What is this type of Testing Procedure called?
The use of sound field audiometry is still employed, but now with visual reinforcement to obtain responses.
A stimulus is played through one of the speakers and a visual reinforcement is used to reinforce the child’s response.
Reinforcement may be a lighted/animated toy, a picture, video or anything that evokes the child’s interest.
Visual Reinforcement Audiometry (VRA)
Sound Field Test Stimuli
Various stimuli are used to elicit responses in the sound field when testing children
There is not a general consensus on which stimuli are best suited for small children
_______ noise is often used to elicit responses due to the child’s frequent response levels.
B. Narrowband
True or False: Due to the band of frequencies that are used, it should be noted that a response to narrowband noise is not the same as a pure-tone response.
