Rehab Audiology Exam 1

4 basic components of rehabilitative audiology

Sensory management, instruction, perceptual training, counseling

International Classification of Functioning, Disability, and Health

Developed by WHO to conceptualize, classify, and describe impact of health-related conditions

Aural habilitation

For very young children with congenital loss; parent advising/counseling

Aural rehabilitation

Restoring lost state or function

Audism

Form of discrimination directed against dDeaf people; notion that people are superior based on the ability to hear and use spoken language

What does an audiogram represent?

The threshold of detection in dB HL of different frequencies measured in Hz

Speech banana

Figurative area on an audiogram that shows us where speech sounds occur

How are audiograms characterized?

Degree, configuration, symmetry, and type of hearing loss

Normal hearing

-10 - 20

Mild hearing loss

20 - 40

Moderate hearing loss

40 - 55

Moderately severe hearing loss

55 - 70

Severe hearing loss

70 - 90

Profound hearing loss

90+

What do low frequency sounds determine?

Prosody

What do high frequency sounds determine?

Clarity

Pure tone average

(Thresholds at 500, 1000, 2000)/3

Sensorineural hearing loss

Impaired air and bone conduction scores with no air-bone gap; damage in the inner ear

Conductive hearing loss

Impaired air conduction scores but normal bone conduction scores; damage in the outer or middle ear

Mixed hearing loss

Impaired bone and air conduction with an air-bone gap; damage in all parts of the ear

What are the different configurations?

Sloping (most common), rising, flat, tent-shape, cookie bite, corner

Prosody

The melody-like aspect of speech that helps convey meaning and emotion

Clarity

How well a listener recognizes what is being said

What is the goal of amplification?

To make inaudible aspects audible

What is the goal of habilitation?

To make speech understandable

Plato on deafness

Deaf are not capable of ideas of language; no signs of intelligence

Aristotle on deafness

Education is impossible without hearing; the deaf are incapable to reason

Early christianity on deafness

Deafness in a child is a punishment by God

Girolamo Cardano

Italian physician who recognized that deaf people could reason

Pedro Ponce de Leon

The first teacher of the deaf; used monk sign language

Samuel Heinicke

Created the first oral school for the deaf in Germany using tactile cues

Charles-Michel de L’Eppe

Established first free public schools for the deaf in France, used fingerspelling and signs

Thomas Braidwood

Used an early form of BSL

Jean Itard and Victor of Aveyron

Conducted research experiments on deaf students to restore hearing

Thomas Galludet and Laurent Clark

Formed the American School for the Deaf

Galludet University

The first and only accredited facility for the advanced education of the deaf and hard of hearing; established in 1864

Alexander Graham Bell

Opened a school in Boston with oral emphasis; viewed negatively by Deaf culture

Conference of Milan (1880)

International consortium of educator endorses oral education over manual; only one delegate was deaf

What happened after WWII?

Hearing rehabilitation became more recognized and different from teaching the congenitally deaf

When were the first electric hearing aids introduced?

1920s

Marion Downs

Initiated practice of fitting hearing aids on infants at 6 months; formed the Joint Committee on Infant Hearing

Babbidge Report

Showed overall weakness in education of D/HH

Julia M. Davis

Began research on hard of hearing children instead of just deaf children

When were cochlear implants invented?

1990-2000

Americans with Disabilities Act

Prohibits discrimination and ensures equal opportunity in multiple aspects of life for Americans with disabilities

Waveform

Changes in amplitude over time

Spectrum

Shows intensity of frequency

Spectrogram

Visual representation of components of speech signal (time, frequency, intensity)

Formants

Acoustic resonances in the vocal tract

Formant transition

Movement of the formant frequency

Vowel production

Open vocal tract, low and mid-frequency acoustic energy, contribute acoustic power, mark syllable’s center or nucleus, longer and slowly changing

Source-filter model of speech production

Source: vibrating vocal folds; filter: vocal tract shape; output: combination of source and filter

Acoustic cues for vowels

Formant 1 and 2

What is formant 1 correlated with?

Tongue height

What is formant 2 correlated with?

Tongue backness

Diphthongs

Combination of two vowels; discriminated based on formant transitions

Formant transitions

Transitions into and out of vowels

Consonant characteristics

Constricted vocal tract, high frequency, low amplitude, change rapidly, mark the edge of syllables

How do we classify consonants?

Voicing, place of articulation, manner of articulation

Place of articulation

Where the airstream is constricted

Manner of articulation

How the airstream is constricted

Least to most constriction

Vowels, semivowels, nasals, stops, fricatives, affricates

Semivowels/approximates

Voiced, minimum constriction; glides and liquids

Nasals

Voiced, airflow through the nasal cavity, determined by pitch cues

What cues are important for manner?

Intensity and frequency

Pitch cues

Frequency of phoneme and direction of formant transition

Stops

Complete closure of vocal tract, consonant release burst

What do voicing cues depend on?

Timing

Voice onset time

Amount of time it takes for voicing of vowel to start

What do manner cues depend on?

Frequency, intensity, and timing

What do place cues depend on?

Frequency

Fricatives

Narrow constriction, generates turbulent airflow

Affricates

Combination of stop and fricative

Hardest to easiest for HL

Place, manner, voicing, nasality

Hard of hearing

PTA between 25 and 75 db HL; benefits from amplification

Severe - profound hearing loss

PTA >= 75 dB HL; no benefit from hearing aids

Auditory capacity

The capacity to detect and discriminate sound patterns

Gain

How much loudness a hearing aid adds

What does configuration determine?

Amount of gain; portions of speech spectrum that can be made audible

Dynamic range

dB difference between softest sound you can hear and loudest sound without pain

Goal of amplification and dynamic range

Keep soft sounds audible but limit discomfort to loud sounds; difficult due to limited frequency range over which sounds are comfortably audible

Auditory resolution

How the inner ear reflects spectral, loudness, and temporal differences among sound patterns; has a direct effect on performance in noisy, reverberant environments

Spectral/frequency resolution

Ability to discriminate between two frequencies; important for understanding speech

Signal-to-noise ratio

Signal: speech; noise: any competing sound; the sound level of the desired signal minus the sound level of the background noise

Positive SNR

Signal louder than noise

Negative SNR

Noise louder than signal

How does distance impact hearing?

As distance from sound increases, intensity decreases (6dB decrease for every doubling of distance)

Reverberation

Repetition of sound waves due to reflection (echoes)

Reverberation time

The duration of time required for reflected sound to be reduced by 60 dB from the cessation of the original sound signal

As the distance from the sound source increases

Intensity decreases and reverberation increases

Auditory performance measures

Clinical assessments of spoken word recognition

Why are performance measures needed?

Validation, determine CI candidacy

Background talker number

Multiple talkers easier than two talkers

Validity

Does the test measure what it’s supposed to?

Reliability

Is the measure consistent across administrators/contexts/over time?

Equivalency

If the test has multiple lists, do patients score the same?

Sensitivity

Is there a significant difference between two test scores?

Basic hearing aid parts

Microphone, amplifier, receiver, battery

Occlusion effect

Takes away natural boost provided by ear canal and makes person’s own voice seem louder

Earmold styles

Full shell, half shell, skeleton