Fundamentals of Audiology for the Speech-Language Pathologist

Vocabulary flashcards covering fundamental concepts in audiology, acoustic physics, middle/inner ear anatomy and physiology, ASHA scopes of practice, and differential diagnosis based on text material.

Audiologist

A professional in research and clinical practice devoted to the study of hearing disorders, assessment of hearing, hearing conservation, and aural rehabilitation.

Speech-Language Pathologist

A professional in research and clinical practice who specializes in the evaluation and treatment of communication and swallowing disorders.

SLP Scope of Practice in Audiology

Includes conducting hearing screenings, managing hearing loss, maintaining hearing aids and assistive devices, and providing counseling; fitting hearing aids is explicitly out of scope.

Preferred Practice Patterns

ASHA policy documents that define the informational base for providing quality patient/client care and focus on professional preparation, continuing education, and research.

ASHA Code of Ethics

The official document outlining ethical principles and standard practices by which all ASHA members and certificate holders are bound.

Person-First Terminology

A 21st-century practice emphasizing the individual before their disability (e.g., using 'student with a hearing loss' or 'child on the autism spectrum' rather than 'hearing impaired' or 'autistic').

International Classification of Functioning (ICF) Framework Diagram

A model representing how body functions, activity limitations, participation restrictions, and contextual factors (environment and personal) interact across prevention, diagnosis, habilitation, rehabilitation, and enhancement.

Sound

A physical phenomenon that describes a movement or vibration of an elastic medium without permanent displacement of the particles, requiring an energy source, a vibrating object, and a transmission medium.

Mass

The physical property describing the quantity of matter present in an object.

Force

A physical push or pull exerted on an object.

Elasticity

The tendency of an object to resist deformity and return to its original rest position after being displaced.

Inertia

The physical tendency of an object to resist any change in its state of motion, governed by Newton's First Law.

Simple Harmonic Motion (SHM)

A continuous, periodic back-and-forth movement (such as a simple pendulum or pure tone) parameterised over time by frequency, amplitude, period, and phase.

Simple Harmonic Motion Diagram

An illustration showing a simple pendulum suspended from a rigid support, oscillating between extreme positions B and C around mean/center position A.

Frequency

The number of complete vibratory cycles (compressions and rarefactions) occurring per unit time (cycles per second), measured in Hertz ($\text{Hz}$); its psychological correlate is pitch.

Amplitude

A derived unit of measurement describing an object's distance from rest to maximal displacement.

Period

The amount of time required to complete one full cycle of vibration, mathematically defined as $\text{Period} = \frac{1}{\text{Frequency}}$.

Phase

The relative timing of compressions and rarefactions of sound waves, describing the specific stage or location at any point in a cycle.

Frequency Waves Diagram

A graphic depicting high-frequency waves (shorter period, more cycles) and low-frequency waves (longer period, fewer cycles), where doubling frequency creates an octave relationship.

Linear vs. Logarithmic Scales Diagram

A diagram contrasting equidistant incremental units on a linear scale with exponential non-linear increments on a logarithmic scale.

Wavelength

The spatial distance covered by one complete wave cycle, calculated as $\text{Wavelength} = \frac{\text{Speed of Sound}}{\text{Frequency}}$.

Speed of Sound

The rate at which sound energy propagates through air, equal to $331\text{m/s}$ at normal atmospheric pressure.

Human Hearing Frequency Range

The acoustic frequency range detectable by normal human ears, spanning from $20\text{Hz}$ to $20{,}000\text{Hz}$.

Just Audible Pressure Threshold

The minimum sound pressure level needed to produce a just audible sound in normal, healthy human ears, equal to 20\text{\thinspace}\text{\textmu Pa} ($0.00002\text{Pa}$).

Threshold of Pain

The sound pressure level at which auditory perception becomes painful, equal to 200{,}000{,}000\text{\thinspace}\text{\textmu Pa}.

Decibel (dB)

A logarithmic (base 10) unit of relative measurement equal to 1/10 of a Bel, expressed as a ratio of measured pressure or power to a standard reference.

Sound Pressure Level Formula

The logarithmic formula used to calculate decibels of sound pressure level: \text{dB SPL} = 20 \times \text{log}\begin{pmatrix}\frac{P_1}{P_2}\right).

Pure Tone

A sound that consists of only one single frequency of vibration.

Absolute Sensitivity

The capability of the auditory system to detect the presence or existence of a sound stimulus.

Differential Sensitivity

The capability of the auditory system to discriminate distinct acoustic features such as differences in frequency, intensity, and timing cues.

Sensation Level (dB SL)

A decibel scale referencing a given number of dB above or below an individual patient's specific hearing threshold for a signal.

Auricle Landmarks Diagram

An anatomical illustration depicting outer ear structures including the helix, antihelix, tragus, antitragus, concha, triangular fossa, intertragal notch, and lobe.

Tympanic Membrane (TM)

The structure separating the outer and middle ear that converts incoming acoustic pressure waves into mechanical energy.

Ossicles

The three smallest bones in the human body located in the middle ear space: malleus (hammer), incus (anvil), and stapes (stirrup).

Eustachian Tube

The canal connecting the middle ear cavity to the nasopharynx; its primary function is pressure equalization and its secondary function is fluid drainage.

Impedance-Matching Transformer

The physiological function of the middle ear mechanism that compensates for energy loss during the transfer from air medium to fluid medium.

Osseous Labyrinth Landmarks Diagram

An anatomical diagram illustrating the bony structure of the inner ear, including the superior, posterior, and lateral semicircular canals, vestibule, cochlea, oval window, and round window.

Cochlear Duct Chambers

The three fluid-filled channels within the cochlea: the upper scala vestibuli (perilymph), middle scala media (endolymph), and lower scala tympani (perilymph).

Organ of Corti

The sensory end organ of hearing located on the basilar membrane inside the scala media, containing inner and outer sensory hair cells.

Outer Hair Cells (OHC)

Sensory hair cells tuned to sound intensity, arranged in 3 rows (approx. 13,000 total) with stereocilia embedded in the tectorial membrane.

Inner Hair Cells (IHC)

Sensory hair cells tuned to sound clarity, arranged in 1 row (approx. 3,500 total) near the tectorial membrane, responsible for stimulating cranial nerve VIII.

Tonotopic Organization

The spatial arrangement of frequency representation along the basilar membrane and auditory pathways, where high frequencies are processed at the base and low frequencies at the apex.

Central Auditory Pathway Diagram

A schematic showing acoustic signal processing from the cochlea through the cochlear nucleus, superior olivary complex, inferior colliculus, and medial geniculate body to the auditory cortex.

Retrocochlear Pathway Sequence

The anatomical pathway of auditory neural signals: CN VIII -> Cochlear Nucleus -> Superior Olivary Complex -> Lateral Lemniscus -> Inferior Colliculus -> Medial Geniculate -> Thalamus -> Heschl's gyrus.

Congenital Hearing Loss Genetics

The epidemiological fact that 75% of hearing loss present at birth (congenital) originates from genetic factors.

ADHD vs. Undiagnosed Hearing Loss Table

A comparative table outlining behavioral differences in inattention, impulsivity, and hyperactivity between diagnosed ADHD and unamplified/undiagnosed hearing loss.

Auditory Fatigue

Cognitive exhaustion resulting from the sustained strain placed on cognitive control and auditory access due to unmanaged hearing loss.

Prenatal Hearing Loss Risk Factors

Maternal conditions during pregnancy that increase risk of infant hearing loss, including CMV, rubella, gestational diabetes, toxemia, herpes simplex, HIV/AIDS, Rh factor incompatibility, and FASD.

Perinatal and Postnatal Hearing Risk Factors

Birth and early childhood risk factors including prematurity, low birth weight, oxygen deprivation, prolonged labor, jaundice, and secondary infections.

Dementia and Hearing Loss Correlation

The clinical relationship showing an accelerated rate of cognitive decline correlated directly with the degree of untreated hearing loss.