SPA 4032 Audiology Final Exam Study Guide

Dr. Cosby's Class

Scope of Practice

What an audiologist or slp does, and their limitations

Code of Ethics

Making sure what an Audiologist or SLP does is ethically sound.

What are the subsystems and subdivisions of the auditory system?

Subsystems: Peripheral Auditory Nervous System, Central Auditory Nervous System

Subdivisions: Outer ear, middle ear, inner ear

Name the landmarks that divide each of the subdivisions in the peripheral auditory nervous system

Landmarks: Tympanic membrane (outer to middle), oval window (middle to inner), cochlea (inner ear structure)

What is the function of the vestibulocochlear nerve?

Transferring hearing and balance information from the inner ear to the brain.

What anatomy controls the interactions from the different systems in the body to help maintain balance from the different systems in the body?

Cerebellum

Where is the vestibule located and what type of fluid is found in the vestibule?

The vestibule is located between the cochlea and the semicircular canals of the inner ear, and it contains perilymph fluid.

Describe the decibel

The unit used to measure the intensity, or loudness, of a sound. It can be described by measuring the power of a signal and comparing it to another pressure. It exists based on a reference, and in the case of hearing, the reference is 20 micropascals, since that is what is just audible to the ear. a decibel is also 1/10th of a Bel.

What are the phases of a sinewave?

Any stage of the cycle of period, condensation, rarefaction, and amplitude over time (PARC). 

A sinewave cycles through 360° of phase:

• 0° – starting point

• 90° – maximum positive displacement

• 180° – back through equilibrium (inverted)

• 270° – maximum negative displacement

• 360° – returns to starting point (one full cycle

Be prepared to know the differences between decibels -know how to reference those decibels (i.e., dB SPL reference=Calibration).

Decibels are usually expressed in different ways depending on the context:

• dB SPL, or decibel sound pressure level, would be used to describe the intensity of a sound for hearing.

• Intensity Level (IL) is the magnitude of sound expressed as power. We don’t want to measure this, however, we want to measure sound pressure. Power is proportional to pressure squared.

• dB SPL = 20 log

Human hearing ranges from 0 (just audible) to 140 dB HL (threshold of pain).

The reason that we don’t use SPL, and we use HL for this measurement is because humans also register different frequencies as well as intensity.

Discomfort is usually 90 dB HL

What is the function of the basilar membrane?

The basilar membrane vibrates in response to sound waves along its length, allowing for the mechanical stimulation of hair cells, which convert mechanical energy into electrical signals for hearing.

What is meant by impedance matching/mismatch?

Impedance refers to opposition to energy flow; in hearing, impedance mismatch between air and cochlear fluid would cause large reflection of sound. The middle ear acts as an “impedance matching device,” providing a bridge between airborne pressure waves at the tympanic membrane and fluid-borne waves in the cochlea.This process enhances sound transmission, allowing for more efficient energy transfer from air to fluid.

In what subdivision of the auditory system does impedance mismatch/matching take place and what anatomy specifically contributes to this process?

The middle ear, specifically the ossicles (malleus, incus, stapes), facilitates impedance matching by amplifying sound vibrations before they enter the cochlea.

How much of a decibel difference does impedance matching account for in the auditory system?

30 dB HL

What parts of the inner ear have perilymph within it versus what parts of the inner ear have endolymph? 

Perilymph is found in the scala vestibuli and scala tympani, while endolymph is located in the cochlear duct (scala media) of the inner ear.

What are the two diagnostic pathways in which sound can be transmitted through the auditory system?

• Air conduction: sound travels through outer ear → middle ear → cochlea → auditory nervous system.

• Bone conduction: vibration of skull directly stimulates cochlea, bypassing outer and middle ear; thresholds plotted separately on audiogram.

Name the ossicles in anatomical order.

Malleus, incus, stapes

Where are the ossicles found in the auditory system?

In between the tympanic membrane and oval window within the temporal bone

Where is the Organ of Corti?

In the cochlea, supported by the basilar membrane within the scala media.

What anatomical structures are located within the Organ of Corti?

Tunnel, Tunnel fibers, Outer hair cells, and deiters cells.

Describe the characteristics of the outer hair cells versus the inner hair cells.

Outer hair cells are responsible for amplifying sound and have a cylindrical shape (there are around 12000), while inner hair cells primarily transmit auditory information to the brain and have a flask-like shape (there are around 3,500).

What are the names of the hair cells in the vestibular system?

Type I and Type II

Names of the semicircular canals (SCC).

Anterior, Posterior, Lateral

What is the function of the SCCs?

The semicircular canals detect rotational movements of the head and contribute to balance by providing information to the brain about these movements.

What is the function of the Utricle and Saccule?

They detect linear acceleration and head position relative to gravity. They play a crucial role in maintaining balance and spatial orientation.

Stereocilia

Stereocilia: small cilia on vestibular hair cells, which are involved in converting mechanical stimuli into neural signals for balance and hearing. They are moved by the fluid moving around them.

Otoconia

Calcium carbonate crystals in otolith membrane, increasing its density. They help detect gravity and linear acceleration.

Macula

sensory area in otolith organs (utricle/saccule) containing hair cells and otoconia. The macula is responsible for detecting changes in head position and linear acceleration, contributing to balance and spatial orientation.

Crista

Sensory area in semicircular canal ampulla containing hair cells.The crista detects rotational movements of the head, contributing to balance and spatial orientation.

Ampulla

Enlarged end of each semicircular canal housing the crista and cupula.

What is the difference between the bony labyrinth vs membranous labyrinth?

• Osseous (bony) labyrinth: channel in the bone.

• Membranous labyrinth: soft-tissue fluid-filled channels within the osseous labyrinth containing the end-organs of hearing and balance

• The fluid within the bony labyrinth is perilymph, while the membranous labyrinth contains endolymph.

Anatomy/function of the outer ear

The outer ear consists of the pinna (auricle) and the auditory canal, which help capture sound waves and direct them toward the tympanic membrane (eardrum). This structure plays a crucial role in the process of hearing.

Passive amplification

Outer ear (auricle/pinna, external auditory canal, outer layer of tympanic membrane) collects and resonates sound, assists localization, and protects the middle ear; the canal and pinna resonances increase sound pressure at the eardrum (passive amplification).

Audiology degree and licensure requirements

The professional degree is the Doctor of Audiology (AuD) as the entry-level clinical degree; audiologists must hold appropriate state licensure to practice.

What is calibration?

Calibration is the process of verifying that audiologic equipment (e.g., audiometers) produces accurate, standardized output levels in dB SPL so that test results are valid and comparable.

What is a biologic check and when is it performed?

A daily listening/biologic check: the audiologist listens to the audiometer/transducers to ensure signals sound normal before clinical use.

What is inverse square law and how does it impact a student with hearing loss?

Sound intensity decreases with distance from the source; as distance from the teacher doubles, intensity at the student’s ear decreases, worsening audibility for a student with hearing loss in a classroom.

Know how to describe the decibel and appropriate decibel references.

The decibel (dB) is a logarithmic unit used to measure sound intensity, often referenced against a standard level such as 20 µPa in air or 0 dB SPL for sound pressure level.

How is sound created?

Sound is created when a force sets an object into vibration in an elastic medium, producing alternating regions of compression and rarefaction that propagate through the medium. 

What is Condensation (compression)/rarefaction for a sound wave?

Condensation (compression) refers to regions in a sound wave where the air molecules are pushed together, resulting in increased pressure, while rarefaction refers to areas where the molecules are spread apart, leading to decreased pressure. These alternating regions create the propagation of sound through a medium.

What are the four properties of sound?

pitch, amplitude, frequency, duration

Afferent versus efferent pathways of sound.

Afferent pathways carry sensory information related to sound from the ear to the brain, while efferent pathways transmit signals from the brain to the auditory system, influencing how sound is processed.
Afferent: sensory fibers carrying information from cochlea/inner hair cells to brainstem and up CANS.

• Efferent: motor fibers from higher centers to cochlea (primarily to outer hair cells)

Definition of Audiology.

Audiology is described as a health care profession that evaluates and manages disorders of hearing and balance.

What is the difference between an Audiometer and an Audiogram?

Audiometer: instrument used to present calibrated acoustic stimuli for testing hearing. Audiogram: graphical representation of hearing threshold levels across different frequencies.

What is otoscopy?

Otoscopy is a medical procedure that involves examining the ear canal and eardrum using an otoscope, allowing healthcare professionals to assess ear health and detect conditions.

1.       Pure tone audiometry procedure/technique for obtaining threshold and what each of the following measures: Air and bone condution, speech audiometry. 

                                                               i.      Speech Reception/Recognition Threshold (SRT)

                                                             ii.      Speech Awareness Threshold (SAT)/Speech Detection Threshold (SDT)

                                                           iii.      Word Recognition Scores (WRS)

                                                            iv.      Pure-tone Average (PTA)

                                                             v.      Most Comfortable Loudness Level (MCL)

                                                            vi.      Uncomfortable Loudness Level (UCL)

Range of human hearing sensitivity (decibels).

The range of human hearing sensitivity typically spans from 0 dB (the faintest sound) to about 140 dB (the threshold of discomfort or pain), which indicates the lowest and highest sound pressure levels humans can detect.

Range of human hearing sensitivity (frequencies).

The range of human hearing sensitivity refers to the frequencies at which humans can detect sounds, typically measured in Hertz (Hz). This range generally spans from 20 Hz to 20,000 Hz.

Definition of threshold.

Threshold refers to the lowest level of sound that an individual can detect or perceive 2/3 times, which is crucial in audiometric testing.

What is the decibel level for threshold of pain?

The decibel level for threshold of pain is typically 140 dB, indicating the point at which sound becomes uncomfortable or damaging to hearing.

Audiogram parameters:
Frequency range for air and bone conduction, and dB range.

An audiogram displays the results of hearing tests, illustrating air and bone conduction thresholds across a frequency range of 250 Hz to 8000 Hz, measured in decibels (dB). It helps evaluate hearing loss by correlating sound intensity with frequency.

Decibel Ranges for Degree of hearing loss.

The ranges for degree of hearing loss categorize hearing impairment as mild, moderate, severe, or profound, based on the quietest sounds that a person can hear, typically measured in decibels (dB).

Normal: 0-25 dB HL

Mild hearing loss: 26-40 dB HL

Moderate: 41- 55 dB HL

Severe: 71-90 dB HL

Profound: 91+ dB HL

Configurations of hearing loss.

Configurations of hearing loss refer to the specific patterns or shapes of hearing impairment observed in an audiogram, which can indicate the cause and characteristics of the hearing loss, such as flat, sloping, or cookie-bite patterns.

Types of hearing loss.

Mixed, conductive, sensorineural

Audiogram key/legend to include color classification used during testing for the right ear versus the left ear.

Left is blue, right is red

What are the different transducers used in pure tone air and bone conduction testing?

Transducers include headphones, sound field, bone oscillators, insert earphones that deliver sound stimuli for accurate hearing assessments.

Name the pathways/substations/relay stations within the Central Auditory Nervous System.

The main pathways include the cochlear nucleus, superior olivary complex, inferior colliculus, and the medial geniculate body.

What is meant by ipsilateral versus contralateral pathways?

Ipsilateral pathways refer to neural pathways that transmit signals to the same side of the brain, while contralateral pathways transmit signals to the opposite side.

Describe/define decussation and indicate the first major processing pathway within the CANS that decussation occurs.

Decussation refers to the crossing over of neural pathways from one side of the nervous system to the other. In the Central Auditory Nervous System, the first major processing pathway where decussation occurs is at the superior olivary complex.

Define Tonotopic Organization and indicate where in the auditory system tonotopic organization occurs.

Tonotopic organization refers to the spatial arrangement of frequencies processed by the auditory system, where different frequencies are represented in specific locations along the auditory pathways. This organization occurs in the cochlea and is maintained throughout the Central Auditory Nervous System, particularly in the basilar membrane.

Describe the function of the Helicotrema

The apex of the cochlea. It connects the scala tympani and scala vestibuli, and allows for movement of fluid between the two. It also equalizes pressure within the cochlea in this way, aiding in sound wave transmission. It slightly impedes the travel of sound (see impedance matching)

Describe the function of the round window relative to the traveling wave in the cochlea.

The round window acts as a pressure relief valve in the cochlea, allowing the fluid movements caused by the traveling wave to dissipate. This function helps facilitate the movement of fluid within the cochlea, ensuring proper transduction of sound waves into neural signals.

What are the different auditory and non-auditory nerves found throughout the auditory system?

Describe sinewave(s): drawing and labeling (Phases) of a sinewave and/or identifying low frequency versus high frequency sinewave.

A sinewave cycles through 360° of phase:

• 0° – starting point

• 90° – maximum positive displacement

• 180° – back through equilibrium (inverted)

• 270° – maximum negative displacement

• 360° – returns to starting point (one full cycle

In terms of frequency, low frequency sinewaves have longer wavelengths and appear more spaced out, while high frequency sinewaves have shorter wavelengths and are more closely packed.

What subdivisions of the ear do air conduction signals pass through versus, what subdivisions of the ear do bone conduction signals pass through?

Air conduction signals pass through the outer ear, middle ear, and inner ear, while bone conduction signals bypass the outer and middle ear, directly stimulating the inner ear.

What is the full objective audiology test battery that can be used to assess the integrity of the auditory system?  

The full objective audiology test battery typically includes auditory brainstem response (ABR), otoacoustic emissions (OAE), and tympanometry. These tests help evaluate the functioning of various parts of the auditory system, including the inner ear and auditory pathways.

What is the full subjective audiology test battery that can be used to diagnosis hearing loss across the lifespan?

The full subjective audiology test battery includes pure-tone audiometry, speech audiometry, and tympanometry. These tests assess hearing sensitivity and speech understanding across different age groups.

What are the three evaluations that are conducted under the Acoustic Immittance Audiometry category?

The three evaluations conducted under Acoustic Immittance Audiometry are static emittance, tympanometry, acoustic reflex threshold

What part(s) of the auditory system are being assessed from Acoustic Immittance testing?

Acoustic Immittance testing assesses the middle ear's function and the integrity of the acoustic reflex pathways.

What specific anatomy is producing the response(s)?

Acoustic Immittance testing assesses the middle ear, cochlea, and auditory nerve. It evaluates the function of the tympanic membrane and the ossicular chain.

What results are we obtaining for tympanometry, versus acoustic reflex testing, versus acoustic reflex decay testing?

Tympanometry evaluates middle ear pressure and compliance, acoustic reflex testing measures the contraction of middle ear muscles in response to loud sounds, and acoustic reflex decay testing assesses the ability of the auditory pathway to maintain the reflex over time.

Be prepared to interpret acoustic immittance audiometry test results.

This involves analyzing tympanometric curves, reflex thresholds, and decay measures to assess middle ear function and auditory pathway integrity.

What nerves are involved at the level of the brainstem arc for acoustic immittance?

• Afferent: CN VIII (cochlear portion) → cochlear nucleus → superior olivary complex

• Efferent: CN VII (facial nerve) → stapedius muscle

Tympanometry-types of tympanograms and classifications produced.

tympanogram type A, Ad, B, C, peak pressure, static admittance, ear canal volume, width/gradient

What is Otoacoustic Emission (OAE) testing?

Otoacoustic Emission (OAE) testing is a non-invasive procedure used to measure sound waves produced in the inner ear, indicating cochlear function. It helps assess hearing ability, particularly in newborns and those with hearing concerns.

What are the names of the two types of OAEs that are clinically used?

Transitory Evoked Otoacoustic Emissions (TEOAEs) and Distortion Product Otoacoustic Emissions (DPOAEs).

What specific anatomy is being assessed during OAE testing?

Otoacoustic emissions assess the functioning of the cochlea, specifically the outer hair cells. This testing helps identify potential hearing loss or abnormalities in cochlear response.

Be prepared to interpret the results from OAE evaluation?

Understanding the presence or absence of otoacoustic emissions can guide decisions regarding further hearing assessments and potential interventions.

What is meant by Signal to Noise Ratio?

Signal to Noise Ratio (SNR) refers to the measurement that compares the level of a desired signal to the level of background noise. A higher SNR indicates clearer signals, which is important for accurate OAE testing outcomes.

Auditory Brainstem Response (ABR) testing-what does it assess?

ABR testing assesses the auditory pathways from the cochlea to the brainstem, measuring the brain's response to sound stimuli.

Auditory Brainstem Response-how many clinical “waves” are produced?

Typically, seven waves are identified in ABR testing, 5 of which are interpreted each representing different auditory pathways.

Auditory Brainstem Response -which waves are used for interpretation?

Waves I to V, are used for interpretation. Waves I, III, and V are primarily analyzed.

Auditory Brainstem Response -which wave is “followed” and critical for interpretating the results?

Wave V is “followed” as intensity decreases and is critical for threshold estimation

Auditory Brainstem Response-what parameters are used to interpret the results?

Latency (timing) and amplitude of waves I, III, V; latency shifts and amplitude reductions are tracked across decreasing intensity, looking for a diagonal pattern; multiple traces are recorded to confirm repeatability and determine threshold (often around 25 dB HL in example).

Be prepared to interpret Auditory Brainstem Response results.

This involves analyzing the latency and amplitude of specific waves (I, III, and V), noting changes in response with decreasing intensity, and confirming repeatability across traces. 1.       WILL BE EXPECTED TO LABEL WAVE 5

Risk factors for hearing loss according to Joint Committee on Infant Hearing (JCIH)

Family history, congenital infections, craniofacial anomalies, low birth weight, hyperbilirubinemia.

What is the timeframe/guidelines provided by the Joint Committee For Infant Hearing (JCIH) associated with the Universal Newborn Hearing Screening (UNHS) program?

The JCIH guidelines recommend that all newborns should be screened for hearing loss by one month of age, those who do not pass the screening should be diagnosed by three months, and appropriate intervention should be provided by six months.

How is speech audiometry assessed for the pediatric population; 0-3 years old versus 3+ years old? 

Speech audiometry for 0-3 years typically involves behavioral observation and play audiometry, while for 3+ years, it integrates standardized word recognition tests and response to auditory stimuli.

a.       Behavioral Observation Audiometry if under 6 months old,

b.       Once we’re at a year, Visual Reinforcement Audiometry

c.       3.5-4 YO conditioned play audiometry

What is the difference between Prelingual/Perilingual/Postlingual considerations in the treatment/management of hearing loss.

Prelingual refers to hearing loss occurring before language acquisition (habilitation), requiring focused early intervention; Perilingual occurs during language development, necessitating tailored strategies; Postlingual involves loss after language is established, often emphasizing rehabilitation and adaptation.

What are surgical options for those with hearing loss who cannot benefit from a hearing aid?

a.       Cochlear implant

b.       Bone anchored hearing aid

c.       Middle ear implant

d.       Auditory brainstem implant

What are some patient characteristics/considerations prior to fitting hearing aids?

Patient age, degree of hearing loss, lifestyle, communication needs, and manual dexterity.

Pediatric Cochlear Implant pediatric candidacy criteria and age range.

a.       Age range: Cochlear America’s: 9 months up

i.      Advanced bionics and MedL: 1 year

1.       Must have bilateral severe-to-profound sensorineural hearing loss

Adult Cochlear implant candidacy criteria and age range.

Typically 18 years or older, must have moderate to profound sensorineural hearing loss in both ears, limited benefit from hearing aids, and motivation to participate in rehabilitation.

Difference between Habilitation and Re(habilitation)?

Habilitation refers to teaching skills to individuals who have never acquired them, typically seen in children, while re(habilitation) involves helping individuals regain skills that have been lost or impaired due to injury or illness.

What are the different types/styles of hearing aids.

There are several types of hearing aids, including behind-the-ear (BTE), in-the-ear (ITE), in-the-canal (ITC), and completely-in-canal (CIC) devices, which vary in size, style, and placement.

What is an Aided Audiogram?

Audiogram that is created with the person having hearing aids on to ensure that they are functioning properly

What objective measure is used to verify the fitting of hearing aids?

Real Ear Measurement (REM)

What are all the components (different sections) that can be found on the audiogram?

Speech audiometry, speech reception threshold, speech awareness threshold, word recognition score, uncomfortable loudness level, most comfortable loudness level, speech recognition, decibel signal to noise ration, pure tone air and bone conduction,

Objective: otoacoustic emissions, auditory brainstem response, tympanometry, acoustic reflect thresholds, acoustic reflex decay

What are appropriate pediatric case history questions to ask?

Questions regarding birth, medical history, developmental milestones, and family hearing loss.

What are appropriate adult case history questions to ask?

Questions about medical history, hearing loss, noise exposure, and communication needs.