Hearing Measurement Lecture l Flashcards
What are the two types of Diagnosis?
Physiological
Rehabilitative
(We tend to focus more on this one as audiologists)
What is our focus as audiologists?
Our focus and goal is the assessment and rehabilitation of receptive communication
Disability is___________________________
Biopsychosocial
What would you call the body of rehabilitative diagnosis?
An impairment (hard of hearing)
What would you call the person of rehabilitative diagnosis?
Activities limitation
What would you call the person in context of rehabilitative diagnosis?
Participation restriction
What issues do we address at the body level (structure and function) during of physiological diagnosis? (4)
Normal/Abnormal
site of lesion
cause
prognosis
What issues do we address person level (activities and participation) during of physiological diagnosis? (5)
- problematic or unproblematic
- hearing capacity (how well can they do)
- is this person having trouble understanding speech
- can we mitigate the effects of the loss
- can we help this person overcome any limitations
Which test is this?
Otoacoustic emissions
Which test is this?
Auditory Brainstem Response
Which tests are these? (2)
Audiogram and Tympanogram
What is this device?
Cochlear Implant
20 Channels, limitation to the number of frequencies it can transfer
What is this device?
Cochlear Implant
20 Channels, limitation to the number of frequencies it can transfer
What was Harvey Fletcher’s experiment? (3)
Experimented by removing parts of the spectrum, and measuring how intelligible the speech was
Foundational research important for the telephone, audiometry, and hearing aid fitting
Developed a method for detecting where speech is.
What can we see from Harvey Fletcher’s result?
Most of the speech information 300 to 3000 Hz most important is at 2000 Hz
What are the general Findings from Harvey’s study?
To understand speech, you need to hear speech features (e.g., formants), which are distributed across the spectrum
Harvey’s study led to the development of an index, what is the name of the index?
The Articulation Index (now the Speech Intelligibility Index)
What does the Articulation Index predicts?
predicts intelligibility from a weighted sum of the audibility (or S/N ratio) in a number of frequency bands
What does the Articulation Index predicts?
predicts intelligibility from a weighted sum of the audibility (or S/N ratio) in a number of frequency bands
How did Harvey conduct his experiment? (2)
Fletcher divided the spectrum into 20 bands
Each band was about 1 mm on the basilar membrane… about 114 IHC
How does Harvey’s study relate to hearing measurement? (2)
You need about 4 features per speech sound
You need about 4 octaves per speech sound
What is an Octave?
Series of notes occupying the interval between (and including) two notes, one having twice or half the frequency of vibration of the other.
What can we conclude from distribution of speech information from Harvey’s study? (3)
- speech information is distributed
- Each phone requires
4 audible octaves or
4 speech features - intelligibility is best predicted by audibility across a wide range
What should we retain about speech perception? (2)
- You need to hear across a wide range of frequencies for speech perception
- Very little detail is needed in any frequency region, so the comparison across frequencies is most important
What do formants reflect and how are they distributed?
Formants or “shape” information reflects the movements of the articulators – this information is distributed across frequency
What is the site of Frequency intergration on the brain (NOT EAR)?
Planum temporale (association cortex) in green
What is the planum temporale involved in?
Tasks that require spectrotemporal integration
What types of potentials does the planum temporale give rise to?
Gives rise to evoked potentials that depend on spectrotemporal integration (the MMN)
Which part on the brain is important for phonology?
Superior temporal sulcus (yellow area)
What are some functions associated with the planum temporale? (give 4)
duration sequences (-silence)
harmonic complexes (-pure tones)
frequency modulated (-pure tones)
amplitude modulated (-steady noise)
spectral motion (-stationary)
pitch sequences (-silence)
melodies (-noise)
speech (-noise)
speech (-complex non-speech)
speech (-tones)
consonant-vowel (-vowel)
unvoiced consonant (-voiced)!!!!
dichotic (-diotic)
lip-reading (-meaningless facial mov’t)
source mov’t versus stationary
What is the name of the ability that shows that details are required for disentangling and tracking voices?
Auditory Scene Analysis
What is the consequence of hearing loss?
Hearing loss produces a disproportionate problem with hearing in noise
What are two problems that hearing loss creates?
- An audibility problem
- A scene analysis problem
What details are important for understanding speech perception in noise?
Fine details are required for hearing noise, tracking voices in space, and disentangling overlapping sounds
What can we say about intelligibility in quiet?
Intelligibility in quiet is best predicted by audibility across the frequencies (details are not necessary)
What do we base our diagnosis of speech limitations?
Primarily based on audibility (pure tone tests)
What are other ways to determine speech understanding problems except with pure tone tests?
Direct testing (Speech in quiet/noise)
Ask them if they can hear in certain context (case history)
The Auditory system is complex – many types of problems can lead to hearing dysfunction, what are they? (5)
- Acoustic system (external ear)
- Mechanical system I (middle ear)
- Mechanical system II (cochlea)
- active and highly-non-linear
- Metabolic system (cochlea)
- Neural system (hair cell transduction, auditory nerve, brainstem, cortex)
Diagnosis is Detective Work
- Used to get dizzy, but no longer
- Tinnitus in right ear
- Asymmetric hearing loss (right worse)
- Reflexes absent with sound to right ear
- ABR I-III and I-V extended (III-V normal)
- Speech perception poorer at high levels
- Reflex decays more than half of its strength within 3 seconds
Right Vestibular schwannoma (Tumor on right side)
Diagnosis is Detective Work
young female athlete
hearing suddenly poorer in left ear after trauma
very high tympanic compliance
word discrimination corresponds to hearing loss
Mechanical issue, Ligament rupturing, Disarticulation
Diagnosis is Detective Work
young woman with an infant
hearing deteriorating over last few years (left ear only)
moderate mixed loss left (normal right), although BC thresholds normal everywhere circa 2 kHz
ipsi reflexes present right, elevated left
word discrimination corresponds to hearing loss
Otosclerosis/ Caharts Notch
Diagnosis is Detective Work
Hears own footsteps
Hears eyeballs moving
Dizzy when loud sounds are presented
Difficulty began after mild trauma to the head
otoacoustic emissions present bilaterally
Crack in the superior semi circular/ superior canal dehiscence
