FSU SPA 4302 Audiology Exam 1

What is audiology?

Audiology is a discipline that focuses on the

assessment and treatment of hearing(auditory)

and balance (vestibular) disorders.

Disciplines related to Audiology

- ENT (medical and surgical specialty related to the ear)

- SLP (prevention, assessment and treatment of speech language disorders, including those with hearing loss)

- Psychology

Frequency range of normal Human hearing

20 - 20,000 Hz

What are the two main professional organizations for

audiologists?

American Academy of Audiology (AAA). and American Speech-Language-Hearing Association

(ASHA)

How and when audiology as a profession first begin?

- Raymond Carhart (1912-1975) is often referred

to as the "father" of audiology

- In 1946, he developed and offered the first

course in "Audiology" at Northwestern

- Created around world war II when veterans returned with hearing loss, Success after the war led to evolution of aural rehab centers in communities around the country (Civilian Sector Expansion), diagnostic Focus, ASHA lifted its ban on audiologists dispensing hearing aids in the late 1970s and the emergence of sub specialty areas of audiology.

What are the academic and clinical requirements that are

needed to become an audiologist?

- The entry-level degree to

practice clinical audiology is Doctor of Audiology (AuD),

which is a 3- to 4-year graduate degree (~75 programs)

o Complete university coursework

o Complete approximately 2000 to 3000 hours of clinical training

o 12-month externship

- Different from PhD (research or academic focus)

What are the legal requirements to practice audiology?

State license

What are the specialty areas within audiology?

Medical Audiology, Educational Audiology, Pediatric Audiology, Rehabilitative Audiology, Industrial

Audiology, University/Research Audiology, Recreational Audiology, Animal Audiology

Settings and audiologist can work in

- schools

- hospitals

- industry setting

- university

- speech and hearing clinic

What are some example of activities that are within an

audiologist's scope of practice?

• Assess hearing

• Prescribe and fit hearing aids/assistive devices

• Assess balance and vestibular function

• Perform balance treatments

• Assess tinnitus

• Perform therapies to improve tinnitus

• Map/program cochlear implants

• Provide aural (re)habilitative services

• Perform inter-operative monitoring for surgeries

• Perform hearing loss prevention activities

• Perform noise surveys

• Work for device manufacturers

How is sound produced?

Sound production requires a vibrating source (e.g., vocal folds) and a medium that is capable of being set into vibration of sound.

• Sounds are pressure waves,

with alternating higher

(compression) and lower

pressure (rarefaction) regions

that move through the medium

- Positive (Higher) pressure (re:

atmospheric pressure): air molecules

bunched up (compression)

- Negative (Lower) pressure (re:

atmospheric pressure): air molecules

spread out (decompression or

rarefaction)

Frequency

the number of cycles (of vibration) per second

amplitude

extenct of vibratory movement of a mass (object) from its position of rest to that point farthest from the position of rest

period

time required to complete a full cycle of vibration

What are the physical and psychological properties of sound

(e.g., a sinewave)?

Pure tone (or sine wave, sinusoid)

- Periodic signals produced by sources vibrating at only one Frequency

- The number of cycles (of vibration) per

second

Amplitude

- intensity (loudness)

Phase: Where a sine wave starts at some arbitrary time

- Measured in degree or radian

- Important for summation of signals

Hearing with two ears

• Important for binaural hearing, e.g., sound localization and

speech perception in noise (a major complaint from individuals

with hearing loss)

Why do we use dB?

- Sounds are pressure waves, i.e., pressure changes relative to

the atmospheric pressure (~105 Pa).

- Sound amplitude (magnitude/intensity) can be measured as

pressure (in the units of Pa or μPa).

- the range of sound pressures that can be heard by humans is

very large. So dB scale was invented!

- The dB scale aligns well

with how human ears

perceive sound amplitude

dB SPL

A purely physical measurement of acoustic pressure in

the air, referenced to the absolute lowest sound pressure detectable by a healthy human ear

at 1000 Hz (20 μPa).

dB HL

A psychoacoustic scale used in clinical audiometry. Because the

human ear is not equally sensitive to all pitches, dB HL normalizes average human hearing

thresholds to 0 dB HL across all frequencies.

Range of dB SPL that humans can hear

0-140 (threshold of pain) dB SLP

What is a complex sound?

containing energy with different

frequencies, amplitudes, and phase relationships.

What is the speech banana?

Speech Banana is a

term used to describe the

area where the phonemes,

or sounds of human speech,

appear on an audiogram.

What is signal-to-noise ratio?

The level of a

desired signal to the level of background noise"

What are the five major components of the auditory system?

- External (Outer) ear

- ME = Middle ear

- CO = Cochlea (Inner ear)

- AN = Auditory nerve

- Central auditory nervous system

What structures constitute the peripheral auditory system?

- External (Outer) ear

- ME = Middle ear

- CO = Cochlea (Inner ear)

- AN = Auditory nerve

Function of outer ear

Conducts sound from

the environment to the

middle ear and modify

(amplify) the acoustic

properties of those

incoming sounds

Function of middle ear

Converts the acoustic

energy from the outer ear

to mechanical energy via

tympanic membrane, and

then pass it on through

the ossicular chain to the

inner ear.

Also amplify the

sounds

Function of inner ear

Convert the

mechanical energy into

electrical impulses that

the brain can interpret

Which structure is responsible for converting acoustic to

mechanical energy?

Middle Ear via the vibration of the tympanic membrane

What is the role of middle ear in sound transduction?

The middle ear serves two key functions in sound transduction:

- Energy conversion & transmission: It transforms incoming acoustic waves into mechanical vibrations at the tympanic membrane and passes them along through the ossicular chain to the inner ear.

- Mechanical amplification (Impedance matching): When sound waves travel from an air medium (low impedance) to a fluid medium inside the cochlea (high impedance), roughly 99.9% of the sound energy (~30 dB) would normally be reflected. The middle ear acts as a mechanical amplifier, providing a total pressure gain of ~30 dB to overcome this impedance mismatch

Which structure is the organ of hearing?

The Organ of Corti, which sits on top of the basilar membrane inside the cochlea, is the organ of hearing

How is sound frequency encoded in the cochlea?

- Sound frequency is encoded by the location of maximum deflection along the basilar membrane:

- High frequencies produce maximum displacement near the base of the cochlea.

- Low frequencies produce maximum displacement toward the apex of the cochlea

Anotia/ Microtia

(outer ear disorder)

Anotia= missing external ear

Microtia = Underdeveloped external ear

Atresia

- (outer ear disorder)

absence of external ear canal

- conductive hearing loss

impacted cerumen

- (inner ear disorder)

accumulation of cerumen that blocks off ear canal; often from cleaning ears with cotton swabs

- mild conductive hearing loss

otitis Media

- (middle ear disorder)

infection of the mucous membrane

lining in the middle ear

Otosclerosis

- (middle ear disorder)

Spongy bone growth over the stapes footplate, in one or both

ears, that fixates the footplate in the oval window, decreasing

effective movement of the ossicular chain

Inner ear disorders

- noise indiced hearing loss

- hearing loss due to aging (presbycusis)

- Acoustic Neuroma (vestibular Shwannoma)

- Meniere's Disease

Ear canal

lateral 1/3 of canal is cartilaginous and produces cerumen

During sound propagation, postive air pressure results from _______, and negative air pressure results from _____.

Compression, Rarefaction

What phase of sound waves causes the tympanic membrane to move inward?

Compression

What is the arrangement of hair cells in the cochlea (organ of corti)

3-5 rows of outer hair cells, and 1 row of inner hair cells

Left vs right TM

Left = 7 o'clock cone of light position; Right= 5 o'clock cone of light position

Formula for calculating dB

dB= 20 x Log ( pressure of measured signal / 20 μPa )

What bones make up the ossicles (in order)

- Malleus

- Incus

-stapes

Tympanic membrane land marks

- cone of light

- annulus

- pars tensa

- Pars flaccida

- manubrium of malleus

- umbo

Major landmarks of outer ear

- Helix

- earlobe

- Tragus

- Antitragus

- concha

Central auditory nervous system

Anatomical structures (be able to label)

•Auditory Cortex (AC)

•Medial Geniculate Body (MGB)

•Inferior colliculus (IC)

•Lateral Lemniscus (LL)

•Superior Olivary Complex (SOC)

•Cochlear Nucleus (CN)

describe the processes that occur in the processing of

sound from the environment through the eighth cranial nerve.

- The outer ear conducts sound from the environment to the middle ear and amplifies the acoustic properties of those incoming sounds.

- The middle ear then converts the acoustic energy from the outer ear to mechanical energy via tympanic membrane, and then passes it on through the ossicular chain to the inner ear. Also amplifies the sound.

- The cochlea converts the mechanical energy into electrical impulses that the brain can interpret.

- The auditory nerve carries the electrical impulses to the central auditory nervous system for further processing and interpretation.

- The central auditory nervous system further processes and interprets the sound.

What auditory structures make up the conductive mechanism?

- Middle ear

- Outer ear

What auditory structures make up the sensory/neural

mechanism?

- central auditory nervous system

- auditory nerve

- cochlea

What is the air conduction pathway?

-Any sound that courses through the outer ear, middle

ear, inner ear, and beyond is heard by air conduction

What is the bone conduction pathway?

-Bypass the outer and middle ear by vibrating the skull

mechanically and stimulating the inner ear directly

Conductive hearing loss

-Occurs when there is a barrier to sound in

the outer or middle ears

•Sound is attenuated - decreased in

strength

Sensory/neural Hearing loss

- Hearing loss related to inner ear, auditory nerve, or beyond

- Sound is attenuated - decreased in strength and distorted

Mixed hearing loss

Disturbances in both the conductive and

sensory/neural mechanisms

Conductive hearing loss would be caused by a problem in the

outer or middle ear

Sensory/ neural hearing loss is couaed by a problem in the

- cochlea or CN VIII

A hearing loss is described as "mixed" if

it has conductive and sensory/neural components

A patient with sensory neural hearing loss would show abnormal results on

both air and bone conduction tests

A patient with conductive hearing loss would show abnormal results on

Air conduction tests

what is the type of transducer for Ac testing or BC testing?

Ac:

- Insert earphones

- supra-aural earphones

- circumaural earphones

- Loudspeakers

BC

- Bone conduction vibrator

What is an audiogram?

a graph the displays the results of a hearing test

Definition of pure-tone threshold

Pure-tone threshold is defined as the lowest intensity level

the patient responds to at least 50% of a series of

ascending (increasing intensity) presentations, with at least

two responses out of at least three trials (up to 4) for a

single level

what is the "up-5-down-10" procedure?

-increase level 5 dB when patient does not hear

-Decrease level 10 dB when patient hears

The most common bone oscillator placement is on the

mastoid

what transducer is typically used for testing bone conduction threshold?

- bone vibrator