Intro final

• creation of a sound source
• vibration of air particles
• reception by the ear
• comprehension by the brain

• the movement or vibration of air particles
• air molecules bump into each other so that the vibration is propagated

the study of sound

• the swing back and forth but don't move far (ripples in a puddle)
• disturbed molecules bunch close together causing areas of compression, then spread apart to return to their original locations, causing areas of rarefaction

• waveforms show the position of air molecules responding to a sound source
• X axis = time
• Y axis = displacement from resting point

• the rate of vibration of the sound source is the frequency of sound
• it is the number of complete cycles of to-and-fro motion that occur in one second

• the time between successive high or low pressure points
• period = 1/frequency (seconds per cycle)

• how fast air particles move back and forth (cycles per second)
• frequency = 1/period

• frequency is measure in Hertz (Hz)
• higher frequency sounds have more vibratory cycles per second than low frequency sounds

• 10 Hz
• the shorter the period, the higher the frequency

• 20 to 20,000 Hz
• the notes on a piano range from 20 to 4,000 Hz

500 to 4,000 Hz

the predominant frequency in a complex waveform

it increases by one octave

• a vibration at only one frequency
• also called a sine wave

• vibration with multiple frequencies produced by the source
• most things including our speech are complex waves

a sound repeats itself at regular intervals

• sound has no repetitive pattern
• white noise is aperiodic

• the pressure produced by the vibrating motion is intensity
• how far apart the particles move when going back and forth

• decibels (dB)
• 0 dB SPL is the perfect hearing threshold

greater air molecule displacement

helps to analyze frequency, intensity, and timing of sounds

• outer ear
• middle ear
• inner ear

• entry point for sound waves
• the visible part of the ear

• gathers and funnels sound waves and channels them inward
• protects the interior of the hearing apparatus from being damaged

the visible part of the outer ear

• lobule- fleshy skin hanging from bottom of pinna
• tragus- hard, cartilaginous triangle that protrudes over the entrance to the auditory canal
• helix- outer body of the pinna

• a short tube shaped as a loose "s" curve leading to tympanic membrane
• conducts sound waves inward

earwax produced by the EAC that traps intruding matter and prevents it from reaching the inner ear

• an air-filed, bony cavity
• transforms acoustic energy to mechanical energy

• tympanic membrane- ear drum
• ossicles- malleus, incus, stapes

• boundary between outer and middle ears
• air-filled, bony cavity

runs from the middle ear to the pharynx and serves as a pressure equalizing tube for the middle ear space

• fluid filled cavity residing in the temporal bone behind the eye socket
• it is a complex system of canals and cavities, somtimes called a labyrinth
• converts mechanical energy to hydraulic energy

power created by compressive force or movement of liquid in a confined area

• vestibule
• semicircular canals
• cochlea

between the cochlea and semicircular canals

open off one side of the vestibule and consist of three canal systems that serve as the organs of balance

• opens off the other side of the vestibule and consists of a single, fluid filled canal that serves as the organ of hearing
• it is a bony, coiled canal in a snail shape and hard walled and fluid filled

• movement of the stapes on the oval window
• the fluid waves carry the auditory info into the cochlea and stimulate the basilar membrane

different places on the membrane are put into vibration with different frequencies of sounds

• the apical end is wider and less stiff
• the apex vibrates mostly to lower frequency sounds and the base to higher frequency sounds

• a long row of hair cells
• sits on the basilar membrane

• they are stimulated by the vibrations of the basilar membrane
• they turn auditory information into neural energy that is transported along the auditory nerve of the brain

• a bundle of nerve fibers that exits the cochlea and travels to the brain
• it is part of cranial nerve VIII (vestibulocochlear nerve)

transports auditory information, in the form of neural energy, from the cochlea to the brain stem, the midbrain, and the cerebrum

receives speech and language stimuli

involved in linguistic comprehension

• processes incoming auditory info that includes both speech and nonspeech
• left = speech and lang. processing within Heschl's gyrus

• sound waves are directed by the pinna into the ear canal
• waves strike the eardrum and cause it to vibrate
• the eardrum is connected to the malleus, which moves the ossicles back and forth (this is the mechanical part of the process)

• the movement of the footplate of the stapes makes waves in the fluid of the cochlea (this is the sensory part of the process)
• pressure of the waves causes the basilar membrane to vibrate, moving the hair cells in the organ of corti
• the movement of the hair cells generates nerve impulses
• the nerve impulses are passed on to the 8th nerve and transmitted to the auditory area of the brain

sound waves travel through the air to the outer ear (starting at the pinna) and are transmitted through the middle ear to the cochlea

• vibrations of bone cause movement in the fluids of the inner ear
• the larger bones of the skull conduct sound because they vibrate in response to airborne sound waves
• we normally hear our own voice through a combination of air-bone conduction sounds

when a child or adolescent is unable to detect or distinguish the range of sounds normally available to the human ear

• location of damage
• which ear(s) are damaged
• chronicity
• origin
• time of onset

• outer
• middle
• inner
• auditory nerve

• short term (ear infection, after a concert)
• long term (grows worse over time)

• could be due to genetics
• or acquired (illness, injury, trauma)

• congenital (present at birth)
• prelingual (soon after birth but before a child has developed language)
• postlingual (after language skills are well established)

• it will result in delayed receptive and expressive speech, and language development (vocab development, use of grammatical morphemes, pragmatic skills, phology can all be negatively impacted)
• children with HL may achieve one to four grade levels less than peers with normal hearing, and the gap may widen over time

• using the decibel (dB) system
• normal, mild, moderate, moderately severe, severe, profound

• hearing level in decibels plotted on a graph
• Y axis = dB and loudness perception
• X axis = frequency range

• it shows where different speech sounds are located perceptually for different dimensions of pitch and amplitude
• you need to have a hearing threshold of below 25 dB SPL at 4,000 Hz to hear fricatives

• a condition in which sound is not "conducted" efficiently through the outer or middle ear, resulting in attenuation of outside loudness
• exaggerates the loudness of the individual's own voice because of bone conduction of sound vibrations

• does not typically result in severe HL because sounds still travel to the brain via bone conduction
• often temporary because it is amenable to surgical or medical intervention

• a viral or bacterial infection of the middle ear space characterized by eustachian tube dysfunction, fluid buulid up, middle ear swelling, and perforated TM
• most common cause of CHL in children

• antibiotics
• pressure equalizing tubes can be inserted through the eardrum to equalize pressure in middle ear and release fluids

• the angle and short length of the eustachian tube makes it easier for organisms to enter and move through the tube
• some environmental allergens
• group child care children are at higher risk (3x more likely)
• cerumen blockage, foreign objects, swimmer's ear, malformations of outer or middle ear

• a HL resulting from damage to the cochlea or auditory nerve that travels from the cochlea to the brain
• results in a decrease in loudness as well as a decrease in speech perception and decreased ability to distinguish speech from background noise

• causes related to genetics, pregnancy, postbirth disease or injury
• often the cause is unknown (50%)

hearing cannot usually be restored, but it can be treated through amplification and other interventions

• occurs when both conductive and sensorineural loss occurs simultaneously
• MHL includes a permanent reduction in sound, as well as an additional temporary loss
• for example, a child with a congenital SNHL may acquire a CHL from a bout of otitis media

• aural habilitation evaluation
• hearing aid evaluation
• comprehensive audiological evaluation
• infant hearing screening (or) conventional hearing screening
• newborn screenings are completed at birth before the child leaves the hospital

• case history and interview
• other interviews and observation
• otoscopic examination
• audiometry
• objective measures

• a lighted magnifying device used to evaulate the structure of the outer and middle ear
• the audiologist inspects the auditory canal and tympanic membrane with an otoscope
• can reveal if there is negative pressure behind the TM, whether the ME is infamed, and if there is fluid in the ME

negative pressure

ME inflammation

fluid in the ME

• also called pure-tone testing
• provides objective information about hearing acuity

• the child to respond to tones, requiring the child's cooperation and participation
• thresholds are obtained for each frequency and are graphed on an audiogram

provide info about the functioning of the outer and middle ear

provide info about the functioning of the cochlea and the auditory nerve

• bone conduction thresholds are normal but diminished air conduction thresholds
• there is a significant air-bone gap (air thresholds problematic but bone thresholds are ok)
• cochlea and auditory nerve are still functioning
• abnormality in outer or middle ear

• decresase in hearing threshold in both air and bone conduction as frequency increases
• no air-bone gap

• combination of sensorineural and conductive loss
• both air and bone conduction thresholds are diminished AND there is a significant air-bone gap
• bone conduction testing problematic, but better than air conduction

• examines tympanic membrane movement or vibration
• evaluates hearing without requiring infant or child to respond

• detected and recorded in ear canal
• when cochlea is impaired, OAEs are abnormal or absent

provide information about the auditory pathway

• ASL or spoken English choices
• education (mainstream or hearing impaired school?)
• amplification devices (hearing aids, assistive listening devices, cochlear implants)

• behind the ear- most common for kids
• in the ear
• in the ear canal

• FM systems- can be used in noisy situations or with distant speakers
• improve a person's hearing ability in difficult listening situations

• surgically placed device that provides electrical stimulaion to the auditory nerve
• 12% use cochlear implants

• microphone converts acoustic to electrical signal
• signal transmitted through skin to an internal receiver implanted in mastoid bone
• signal is transmitted to electrodes in the cochlea which then deliver sound to the auditory nerve

• required for children with HL learning to use oral language
• ensuring an appropriate listening environment by minimizing auditory distractions
• maximize audition by maintaining the quality of the ALD
• adults should enhance the acoustic signal to provde more audible cues during interactions
• support listening development by coupling auditory and visual cues and gradually increasing auditory demands

• single most important factor in determining long-term achievement for children with HL
• intervention for infants, toddlers, and preschoolers

• parental involvement to expose children to language learning opportunities
• naturalistic environments to facilitate carryover
• support development within the context of authentic social interactions
• develop capacity for functional communication in everyday contexts

• an effective means of communication must be established (signs with oral language or cochlear implant)
• self-advocate outside home
• consistent and intensive support to achieve literacy and literate thought

• neurological problem that adversely affect an individual's processing, or interpretation, of auditory messages, even though hearing acuity is intact
• little difficulty with speech production, but vocab development, pragmatics, listening, and academic achievement may be affected
• amplification is not an option becaus difficulties are not related to hearing acuity

• more than 31 million
• 10% of the population
• over 1/4 of the adult population will experience a HL in their lifetime
• 90% of persons over the age of 80 have hearing loss

• perception that HL is not severe enough
• costs for treatment
• negativity about hearing aids
• hearing screenings occur infrequently at routine medical visits

• sensorineural
• cochlea and auditory nerve most affected by aging, noise exposure, illness, disease, and injury

HL that occurs as a result of age

• social-emotional (higher rates of depression, etc)
• psychological
• physical

• aging
• noise exposure/damage
• head trauma
• tumor
• ototoxic drugs
• infection/disease/illness

• mild (26-40 dB)
• moderate
• moderately severe
• severe
• profound (>91 dB)
• normal hearing is -10-25 dB)

• cerumen blockage
• foreign objects in ear canal
• otitis media
• damage to outer or middle ear
• otosclerosis (abnormal bone growth around ossicles)- 2:1 ratio of women to men

• consonants, particularly voiceless fricatives
• affricates
• stops

• noise-induced HL results from exposure to damaging level of noise (greater than 85 dB)
• meniere's disease and tinnitus
• acoustic neuromas- tumors on the auditory nerve
• meningitis, cerebral-vascular disease, diabetes, etc

taking ototoxic drugs can damage the hearing mechanism

• a comprehensive plan combining:
• counseling
• fitting of amplification devices
• aural rehabilitation