Comprehensive Study Guide on Hearing, Acoustic Cues, and Speech Perception (copy)

Audition

The detection and transmission of sound waves through peripheral and central auditory structures to the brain.

Speech perception

The higher-level neurocognitive interpretation of incoming auditory signals into linguistically meaningful units.

Acoustic cue

The objective, measurable physical property of a sound wave (e.g., formant frequency, VOT) that helps listeners identify and differentiate phonemic categories.

Frequency

The rate of acoustic pressure wave oscillation, which correlates perceptually with pitch.

Amplitude

The magnitude of acoustic pressure variations, which correlates perceptually with loudness.

Pinna

The outer ear structure that collects sound and funnels it into the ear canal; also called the auricle or external ear.

External auditory meatus (EAM)

The tubular conduit running from the pinna to the tympanic membrane; also called the ear canal.

Tympanic membrane

The thin, semi-translucent fibrous barrier between the outer and middle ear; also called the eardrum.

Ossicular chain

The three smallest bones in the human body, linked in sequence as malleus, incus, and stapes.

Malleus

The ossicle attached to the tympanic membrane; also called the hammer.

Incus

The intermediate ossicle that links the malleus and stapes; also called the anvil.

Stapes

The medial-most ossicle whose footplate inserts into the oval window; also called the stirrup.

Oval window

The membrane-covered opening into the inner ear vestibule that receives vibrations of the stapes footplate.

Round window

A membrane-covered aperture below the oval window that relieves pressure from incompressible cochlear fluid.

Eustachian tube

A channel from the middle ear to the nasopharynx that equalizes air pressure across the tympanic membrane; also called the auditory tube.

Acoustic reflex

The reflex contraction of the stapedius and tensor tympani muscles in response to sustained loud sounds, stiffening the ossicular chain to reduce transmission.

Cochlea

The coiled, snail-shaped bony structure of the inner ear dedicated to acoustic transduction.

Basilar membrane

A flexible partition in the cochlea that vibrates in response to hydraulic traveling waves.

Organ of Corti

The sensory receptor organ on the basilar membrane containing hair cells with stereocilia.

Tectorial membrane

A gelatinous, acellular flap over the organ of Corti against which hair cell stereocilia are deflected.

Tonotopic organization

The organization of the cochlea in which high frequencies map to the base and low frequencies map to the apex.

Place coding

The mechanism by which nerve fibers are coded for frequency by firing at specific positions along the basilar membrane.

Phase locking

The synchronization of nerve fiber action potentials to particular phases of a sound wave, especially for low-frequency sounds.

Auditory nerve (CN VIII)

The cranial nerve VIII branch carrying auditory signals from the cochlea to the brainstem.

Heschl's gyrus

The auditory cortex region on the superior temporal lobe where ascending auditory signals terminate.

Hearing impairment

Hearing loss from peripheral damage that reduces access to the acoustic signal and can compromise language acquisition.

Auditory agnosia

A clinical condition with normal pure-tone hearing sensitivity but an inability to recognize or assign meaning to familiar sounds or words.

Fundamental frequency (F0)

The fundamental frequency of vocal fold vibration, perceived as vocal pitch.

Formant

Resonance peaks in the vocal tract that shape the glottal source into energy peaks; F1 relates to tongue height and F2 to tongue advancement.

Voice onset time (VOT)

The temporal gap between the release burst of a stop and the onset of vocal fold vibration.

Diphthong

The continuous glide between two vowel configurations within a single syllable nucleus, as in /aɪ/.

Categorical perception

The perceptual phenomenon in which continuous acoustic variation is perceived as discrete phonemic categories.

Phonetic mode

The listener's attention to sounds as linguistic speech tokens, such as classifying a sound as /b/ or /p/.

Auditory mode

The listener's attention to the raw physical characteristics of a sound, such as pitch or timing.

Echoic memory (precategorical acoustic storage)

A brief, highly accurate, unanalyzed sensory trace of raw acoustic input that persists for several seconds.

Lack of acoustic invariance

The variable acoustic properties of a phone across speakers and contexts that prevent a one-to-one mapping to phonemes.

Coarticulation

The blending of neighboring speech sounds because articulators move continuously.

Motor theory of speech perception

The theory that listeners perceive speech by recovering the intended articulatory gestures that produced it.

Auditory theory of speech perception

The theory that speech is perceived by analyzing acoustic patterns directly, without reconstructing motor gestures.

Analysis-by-synthesis

A model in which listeners generate hypothetical articulatory patterns and compare their acoustic output with the incoming signal.

Right ear advantage (REA)

The advantage for verbal stimuli presented to the right ear in dichotic listening, reflecting left-hemisphere language processing.

Critical period hypothesis

The theory that developmental flexibility for language acquisition peaks early in childhood and declines with maturation.