Audiology Midterm

Father of Audiology

Raymond Carhart developed the term 'audiology' as the science of hearing after being commissioned by the Army to lead the aural rehabilitation program for the military.

Emergence of Audiology

The profession of Audiology emerged after WWII when military members returned home with hearing loss due to noise exposure.

Medical Audiologist

An Audiologist who works in a hospital satellite office with Otolaryngologists.

Parts of the Ear

There are three main parts of the ear: Outer, middle, and inner.

Outer Ear Parts

Auricle/Pinna, External Auditory Meatus (Ear Canal), Tympanic Membrane (Ear Drum).

Functions of the Outer Ear

Protects the delicate middle and inner ear structures from foreign bodies, amplifies high frequency sounds, provides the primary cue for the determination of the elevation of a sound source.

Parts of the Pinna

Helix, Concha, Ear Lobe, Tragus, Antitragus.

Middle Ear Parts

Tympanic Membrane, Ossicular Chain, Eustachian tube.

Ossicular Chain

Three bones linked together (articulating) in the middle ear.

Eustachian Tube

Tube that runs from the middle ear cavity to the nasopharynx, functions to drain the middle ear cavity of fluid and to provide air within that space.

Malleus

Also known as the 'Hammer', articulates with the Tympanic Membrane and the Incus.

Incus

Also known as the 'Anvil', articulates with the Malleus and the Stapes.

Stapes

Also known as the 'Stirrup', articulates with the Incus and attaches to the Oval Window of the Cochlea.

Vestibular System

A sensory system in the inner ear that is essential for maintaining balance, spatial orientation, and coordinating eye movements.

Inner Hair Cells vs Outer Hair Cells

Inner Hair Cells are located in 1 row along the basilar membrane while Outer Hair Cells are located in 3 rows along the basilar membrane.

Organ of Corti

The organ that houses all hair cells within the inner ear.

Tonotopic Organization

Means it is tuned to receive sounds of different frequencies at specific locations.

VIII - Vestibulocochlear cranial nerve

Helps conduct neural impulses from the cochlea to the brain.

Vestibular branch

Part of the vestibulocochlear nerve responsible for balance.

Cochlear branch

Part of the vestibulocochlear nerve responsible for hearing.

Loudness

Measured in decibels (dB).

Pitch

Measured in Hertz (Hz).

Amplitude increase effect on loudness

As the amplitude increases, loudness increases.

Wavelength increase effect on frequency

As wavelength increases, frequency decreases.

1st trimester embryologic development

The outer, middle and inner ear begin to develop.

Pharyngeal arches and clefts

Become apparent around Week 4 of pregnancy.

2nd trimester cochlear development

The cochlea matures, nerve fibers form, and brainstem nuclei develop.

EAC formation in 2nd trimester

By the end of the second trimester, the external auditory canal (EAC) is fully formed.

EAC solid plug

Forms during week 16 as a temporary blockage.

Meatal plug dissolution

Occurs by week 21-28.

3rd trimester facial nerve development

The facial nerve is formed and myelin appears.

Development of auditory and communication skills

Is predictable, happens in phases, milestones are typically attained within an expected time frame, individuals can vary, and requires exposure and opportunities to practice.

Signs of hearing loss in children

Babbling that stopped around 6 months of age, delayed speech and language skills, frequent ear infections, lack of attention, sitting too close to the TV, poor school performance.

Signs of hearing loss in adults

Difficulty hearing voices, especially in noisy environments, turning the TV up too high, mishearing, and difficulty talking on the telephone.

Negative effects of untreated hearing loss

May negatively affect overall development, language, social, psychological, cognitive aspects, increases risk for dementia, and has financial and emotional impacts.

Population percentage with hearing loss aged 70-79

54.6%.

Otitis Media

An infection in the middle ear space.

Stenosis

Narrowing of the ear canal.

Wax impaction

Blockage of the ear canal due to earwax buildup.

Exostoses

Bony growths in the ear canal that can completely block it.

Otitis externa

Swimmer's ear that causes sufficient swelling to block the ear canal.

Congenital malformations

Anomalies such as microtia and atresia affecting ear structure.

Presbycusis

Age-related hearing loss characterized by gradual reduction of hearing over time.

Sensorineural Hearing Loss (SNHL)

Hearing loss due to dysfunction of the inner ear, often from damaged hair cells in the cochlea.

Noise Induced hearing loss

Hearing loss caused by exposure to loud sounds.

Infectious disease

Diseases like meningitis or measles that can lead to hearing loss.

Ototoxicity

Hearing loss resulting from medical treatments, such as certain antibiotics or chemotherapy.

Meniere's Disease

A disorder of the inner ear resulting in fluctuating hearing loss, vertigo, tinnitus, and aural fullness.

Air-bone gap

A greater than 15 dB difference between air and bone-conduction thresholds.

WRS

Word Recognition Score, a test using one-syllable words presented at 40 dB above the Speech Reception Threshold (SRT).

Visual Reinforcement Audiometry (VRA)

A hearing test for children aged 6 months to 2 years.

Conditioned Play Audiometry (CPA)

A hearing test for children aged 2-5 years.

Speech Reception Threshold (SRT)

The minimum hearing level for speech at which an individual can recognize 75% of the speech material.

Spondees

Two-syllable words with equal stress on both syllables used in SRT testing.

WRS testing purpose

To assess the clarity of speech stimuli presented to a patient at a comfortable level.

Case History

A review of the patient's medical history and previous audiological evaluations.

Informal Observation

A non-standardized assessment of a patient's hearing ability in everyday situations.

Otoscopy

An examination of the ear canal and eardrum using an otoscope.

Pure-Tone testing (air conduction & bone conduction)

A method to assess hearing sensitivity using pure tones presented through air and bone conduction.

Speech Testing

An evaluation of a patient's ability to understand and repeat spoken words.

Immittance (Middle Ear) Testing

A test that assesses the function of the middle ear and the mobility of the eardrum.

Tympanometry

The only objective measurement in a standard audiological test battery.

Range of normal hearing in adults

Typically from ________dB to ________dB.

Noise notched hearing loss

Most significant dip at 4,000 Hz followed by a recovery in higher frequencies/thresholds.

Threshold

The softest level at which a patient can hear a sound, determined through specific testing methods.

Conductive hearing loss

Caused by an abnormal reduction or attenuation of sound as it travels from the outer ear to the inner ear.

Mixed Hearing Loss

Refers to a loss with both a conductive and sensorineural component.

Mixed Hearing Loss Characteristics

SNHL portion is permanent, but the conductive component may improve.

Central Hearing Loss

Hearing loss that is related to damage beyond the cochlea either along the auditory nerve (8th cranial nerve) or in areas of the brain that process auditory information.

Functional Hearing Loss

Hearing loss that is non-organic in nature; There is no underlying structural or physiological damage to the auditory system.

Flat Configuration

Tend to stay within 15 dB of each other; Bilateral and symmetrical; Oftentimes are seen when a hearing loss has progressed to be more severe or profound, eliciting a flat response.

Sloping Configuration

Most common configuration; Best response in the low frequencies, as audiogram progresses, the hearing loss gets more severe.

Rising Configuration

Shows better hearing in the high frequencies and poorer hearing in the low frequencies.

Noise-Notched Configuration

Most significant dip at 4,000 Hz followed by a recovery in higher frequencies/thresholds.

Cookie Bite or U-Shaped Configuration

Oftentimes there is a genetic component; Lower dip around 1,000 Hz with some recovery following.

Reverse Cookie Bite or Reverse U-Shaped Configuration

Accompanies genetic/hereditary hearing loss; Best hearing threshold is around 1,000 Hz with a decrease on either side.

High Frequency Configuration

This is also a sloping configuration; Must involve high frequency.

Low Frequency Configuration

This is also a rising configuration.

Unilateral Hearing Loss

Hearing loss that presents in one ear only; Hearing in the other ear is within normal limits (WNL).

Bilateral Hearing Loss

Both ears have a hearing loss.

Symmetrical Hearing Loss

Same hearing loss in each ear; Same type, degree, configuration.

Asymmetrical Hearing Loss

Different hearing loss in each ear; Can differ by type, degree, and configuration.

Hearing Loss Symbols

Red, Right, Round! Blue=Left; Brackets mean bone.