Section 11 Flashcards
Name and define the three types of hearing loss.
Conductive: problem in outer/middle ear spaces resulting in sound not being properly conducted to inner ear.
Sensroineural: problem in inner ear (damage to the inner hair cells of the cochlea or auditory nerve), permanent.
Mixed: both a contribution from an outer/middle ear problem and an inner ear problem.
What are some perinatal risk factors forbearing loss?
Family history of pediatric HL
Low birth weight
Prematurity (<= 30 weeks)
Persistent pulmonary hypertension of the newborn
Hypoxic-ischemic encephalopathy
Intraventricular & periventricular hemorrhage
Congenital diaphragmatic hernia
Ventilation support
Infections at birth (HIV, measles, mumps, TORCH, CMV, meningitis)
Obvious craniofacial malformation of external ear canal
Severe neonatal sepsis
Severe hyperbilirubinemia/ kernicterus
Severe neonatal asphyxia/hypoxia/respiratory failure/cardiopulmonary failure
Syndromes including Down syndrome, CHARGE, Usher’s, Waardenburg, Treacher Collins, Hunter, and more
What are some outer ear pathologies that could result in hearing loss?
Microtia: under-development of the pinna
Atresia: closing or absence of an ear canal resulting in permanent conductive hearing loss.
Stenosis: narrowing of the ear canal
Otitis externa: water pooling in the ear causing bacteria to grow in the eat canal and cause infection (swimmer’s ear)
Otomycosis: fungal infection caused by overuse of ear drops.
TM perforation: rupturing of the eardrum caused by excessive fluid in middle ear (otitis media), trauma, or object insertion.
Benign growth: exostoses (surfers ear - irregular bony growth in EAM), osteromas (smooth bony know in cartilage-bony junction)
Collapsed ear canal
Foreign bodies and impacted cerumen (wax)
Congenital malformations
Structural changes secondary to infection or trauma
Medical conditions
What is otitis media and the risk factors associated with it?
Inflammation of the middle ear, usually the result of poor Eustachian tube function.
Otitis media with effusion (OME) = inflammation of the middle ear with fluid.
Risk Factors for Children: Family history, Seasonal variation (increased occurrence in fall and winter), Daycare/child care environment, Infant feeding (breast vs. bottle - bottle-fed babies tend to have OM more than breastfed babies), Exposure to smoke, Gender (increased occurrence with males), Children less than 24 months old, Allergies/ frequent colds
Populations at greater risk: down syndrome, cleft lip and palate, fetal alcohol syndrome, native canadians, children in general
What are the different classifications of otitis media?
Acute OM = occurs <3 weeks, rapid onset & rapid resolution
Subacute OM = persists beyond the acute stage, 4-8 weeks
Chronic OM = slow onset and lasts >9 weeks
Recurrent OM = 3+ episodes within a 6-month period
Serous OM = thin/watery fluid; middle ear fluid without bacteria/debris & associated symptoms, except for conductive hearing loss (also referred to as OME)
Suppurative (Purulent) OM = sticky/thick fluid; bacteria & debris are present in the fluid
What are some middle ear pathologies associated with hearing loss?
Tympanosclerosis: sever form of scaring in the middle layer of tympanic membrane from chronic inflammation, trauma, or ventilation tubes, resulting in stiffening of ossicles or fixation of chain
Otosclerosis: bony growth in footplate of stapes and oval window region causing stapes to become rigid and not allowing the oval window to create pressure waves in inner ear (strong genetic link mostly in pregnant women)
Cholesteatoma: skin growth found in abnormal location, namely behind the tympanic membrane.
Otomycosis: fungal infection caused by overuse of eye drops.
Discontinuity of the ossicular chain: disruption of attachments caused by congenital defects, skill trauma, and middle ear disease.
Syndromes and other medical conditions such as facial nerve (CN VII) disorders (eg. bells palsy), down syndrome, treacher cowlings syndrome, cleft lip and palate.
Congenital malformations
Structural changes secondary to infection or trauma
What are some inner ear pathologies associated with hearing loss?
Structural defects due to embryological malformations
Structural changes secondary to infections
Inherited conditions
Acoustic trauma, infections, ototoxicity
Presbycusis (sensorineural hearing loss associated with aging)
What is auditory processing?
Auditory processing ability is the capacity with which the central auditory nervous system transfers information from the 8th cranial nerve to the auditory cortex. APD is an impairment in this function of the central auditory nervous system
What is auditory processing disorder?
Auditory Processing = when the brain recognizes and interprets sounds and surpasses unwanted sounds
APD means that something is adversely affecting the processing or interpretation of the information
Can hear information but have difficulty attenting to, storing, locating, retrieving, and/or clarifying that information to make it useful.
What are some possible causes of APD?
Possible Causes in Children: ○ Auditory deprivation (i.e. history of otitis media) ○ Genetic factors ○ Birth trauma ○ Maturational delays in CNS
Possible Causes in Adults:
○ 8th cranial nerve (i.e. Cochleovestibular Schwannoma)
○ Brainstem (i.e. multiple sclerosis)
○ Cortex (i.e. tumour, trauma)
○ Diffuse (i.e. meningitis, toxicity, deprivational effects of peripheral pathological conditions, degenerative effects of aging)
What are the different degrees of hearing loss?
Slight (16-25dB): hearing across the speech spectrum is sufficient in quiet situations, difficulty with higher frequency consonants in noise may cause impaired speech perception.
Mild (26-40dB): louder components of the speech spectrum (ie. vowels) are audible, some crucial consonant sounds (/th, /f/, /s/, /k/, /t/) may be difficult to hear or missed, even in good environments.
Moderate (41-55dB): much of the speech spectrum is barely audible, with mostly vowels and only a few consonants heard, listening at a distance of in noise is very difficult and listening is fatiguing at all times.
Moderate-severe (56-70 dB): normal conversational speech is essentially inaudible, louder environmental sounds, such as car horn or fire alarm, are audible.
Severe (71-90dB): speech is not audible unless spoke next to the ear, louder environmental sounds may be audible but soft.
Profound (91+ dB): total lack of hearing, may rely mainly on lip-reading and/or SL, or cochlear implant.
Why is hearing important to speech?
Hearing supports the acquisition & production of speech and language in several ways. Hearing allows infants to be aware of environmental and speech sounds, as well as makes it possible to understand
spoken language.
Hearing is necessary in monitoring one’s own production of speech and language (how & what we say). People with hearing impairments have challenges in monitoring their speech, language, and voice productions.
What are some variables that that impact the effect hearing loss has on speech, language and voice?
Age of onset of the hearing loss & the degree of loss.
Congenital hearing loss (present at birth) has a greater impact than hearing loss acquired later in adult life.
Pre-lingual hearing loss = the individual experiences hearing loss before they acquire speech & language
Post-lingual hearing loss = the individual experiences hearing loss after the acquisition of speech and some language (usually after 5 years old)
How does hearing loss impact speech in children?
Distortion of sounds (especially fricatives & stops)
Children with hearing loss often cannot hear /s/, /sh/, /f/, /t/, /k/, so they do not include them in their speech & as a result, their speech may be difficult to understand
Omission of initial & final consonants
Consonant cluster reduction
Substitution of voiced consonants for voiceless consonants (e.g. /g/ for /k/)
Omission of /s/ in almost all positions of words
Substitution of nasal consonants for oral consonants (e.g. mat/bat)
Increased duration of vowels
Imprecise production of vowels
Epenthesis, or adding a schwa sound to consonant blends
How does hearing loss impact language?
Use of limited variety of sentence types
Sentences of reduced length & complexity
Difficulty comprehending and producing compound, complex, and embedded sentences
Limited oral communication, including lack of elaborated speech and reluctance to speak
Slower acquisition of grammatical morphemes
Omission or inconsistent use of many morphemes (e.g. past tense & plural inflections, present progressive -ing, prepositions, conjunctions, etc.)
Poor reading comprehension
Writing that reflects oral language problems (e.g. deviant syntax, limited variety of sentence types, omission of grammatical morphemes)
How does hearing loss impact voice, fluency, and resonance?
Hypernasal or hyponasal resonance
Abnormal phrasing, flow, or rhythm of speech
Monotone speech with lack of appropriate intonation
Improper stress patterns
Restricted pitch range
Too fast or too slow rate of speech
Inappropriate pausing
Inefficient breathing, including breathiness
Deviations in voice quality, including hoarseness & harshness
Discuss how the various levels of hearing loss may impact speech understanding.
Slight/Minimal HL = individual may miss 10-20% of speech signal is the speaker is more than 3 feet away or the room is noisy
Mild Loss = miss between 25-50% of the speech signal
Moderate Loss = miss 50-75% of speech signal
Severe Loss = can miss up to 100% of the speech signal
Individuals with unilateral hearing loss may have difficulty with soft speech or speech at a distance, as well as hearing in noise
How does auditory processing disorder impact
Inordinate difficulty hearing in noisy or reverberant environments
Lack of music appreciation
Difficulty learning new words, following multi-step directions/instructions, learning a foreign language, directing, sustaining, or dividing attention
Auditory memory deficits
Reading, spelling, and vocabulary difficulties
Organizational problems
Behavioural, psychological, and/or social problems
Difficulty remembering spoken language and with phonemic awareness and sound manipulation
Easily fatigued
Problems with dichotic listening (i.e. child has trouble understanding competing, meaningful speech/sounds that happen at the same time)
Trouble with auditory closure (i.e. “filling in the gaps” when speech is more challenging to hear)
Temporal processing challenges (i.e. recognizing differences in speech sounds)
Difficulty understanding pitch and intonation
Problems with binaural interaction (i.e. the ability to know which side speech/sounds are coming
from, and to localize sound in a room)
Compare the terms deaf and Deaf.
Deaf: identify with a cultural community of people who are also Deaf, typically use SL as primary communication, has own norms and values.
deaf: individuals who have hearing loss but do not identify as Deaf and usually use spoken language
What is the source-filter theory of speech production?
The complex vibration of the vocal folds generates a source signal with many harmonics
The source signal is then filtered by the vocal tract
The signal finally dissipates from the lips into the air, where it is transmitted as pressure variations through space (output)
Source = glottis
Filter = vocal tract
Output = speech signal
Define fundamental frequency.
The rate at which the vocal folds vibrate
Characteristic of the source signal
Vibrations occur in cycles that are measured per second & frequency refers to the number of times a cycle of vibration repeats itself within a second (measure in Hertz [Hz])
How can hearing loss impact education and vocation?
Language deficit causes learning problems that result in reduce academic achievement
Communication difficulties often lead to social isolation & poor self-concept
Children with HL are more likely to fail a grade & exhibit behavioural problems at school
If a child has difficulty hearing in the classroom (whether caused by a hearing loss or poor listening environment or both), research indicates that reading, writing, staying “on task,” spoken language, academic performance, and psychosocial behaviours can be suppressed
APD can result in difficulty taking notes during lectures and learning technical or discipline-specific vocabulary where the language is largely unfamiliar or novel .
