speech and hearing science exam #3 video review questions

What is categorical perception?

Perceiving speech in categories rather than continuous acoustic changes

Why can small acoustic changes cause big perceptual differences?

Because listeners perceive categories, not gradual shifts

What speech features show categorical perception?

Stop place, fricative place, and VOT

What does the motor theory claim?

We perceive speech by accessing human articulatory gestures

Is motor theory human-specific?

yes

How does motor theory handle acoustic variability?

It extracts stable articulatory gestures from variable acoustics

What is duplex perception?

Hearing both a speech syllable and a non-speech chirp when cues are separated

Is duplex perception strong evidence for motor theory?

No, because it is also seen with non-speech sounds

What do general auditory theories rely on?

Acoustic signal + top-down linguistic/semantic information

How do they solve acoustic invariance?

By using consistent acoustic patterns across speakers

What is statistical learning?

Learning categories through exposure to recurring patterns

What is speaker (talker) normalization?

Adjusting perception to individual voices, accents, or dialects

What does direct realism propose?

Listeners perceive articulatory events directly, not acoustics

How do auditory theories explain vowel learning?

Through statistical learning and normalization

What does direct realism say about vowels?

They are perceived as articulatory gestures

Do listeners need full acoustic detail for word recognition?

No

What helps identify words?

Acoustic cues → phoneme categories → lexical activation + context

Why are words easier to understand than isolated sounds?

Context helps identification

What is an equal-appearing interval scale?

A 1–5 scale assuming equal perceptual spacing

What is Direct Magnitude Estimation (DME)?

Rating relative to a reference number (usually 50)

What is phonetic transcription used for?

Writing exactly what the listener heard

What is the main function of the pinna?

Collects and funnels sound

What is the outer ear overall function?

Acts as a resonator that amplifies frequencies

What does the tympanic membrane?

Outer ear and middle ear

Name the three ossicles

Malleus, incus, stapes

What structure does the stapes attach to?

oval window

What does the Eustachian tube do?

equalize pressure

What is the MOST important concept behind impedance matching?

Pressure increases when area decreases (TM → OW)

What contributes to impedance matching besides area ratio?

Lever action of ossicles + TM shape

Which structure detects angular acceleration?

semicircular canals

Which structures detect linear acceleration?

Utricle and saccule

what do inner hair cells do?

sensory receptors for hearing

What do outer hair cells do?

Amplify and fine-tune cochlear vibrations

What frequencies are at the base of the cochlea?

high frequencies

What frequencies are at the apex of the cochlea?

low frequencies

Do both ears send information to both hemispheres?

yes, bilateral innervation

What is the acoustic reflex?

Middle ear muscle response to loud sounds

Difference between intensity and loudness?

Intensity = physical; loudness = perceptual

What are phons?

Units representing equal-loudness contours

What are sones?

A scale where doubling the number = doubling perceived loudness

Why does noise sound louder than pure tones?

Contains many frequencies (more total energy)

What is frequency?

Physical vibration rate (Hz)

What is pitch?

perceived tone height

is pitch perception linear with frequency?

no

Is pitch perception linear with frequency?

no

What is ITD best for? (interaural time difference)

localizing low frequencies

What is ILD best for? (Interaural Level Differences)

localizing high frequencies

What is the cocktail party effect?

Ability to focus on one voice in a noisy environment

What does the CNS include?

brain and spinal cord

What does the PNS include?

cranial and spinal cord

Difference between gray & white matter?

Gray = cell bodies, white = myelinated axons

Which hemisphere is dominant for speech?

left

What does the frontal lobe control?

Motor planning, movement, Broca’s area, executive functions

What does the parietal lobe do?

Sensory processing, language-related integration

What does the temporal lobe include?

Primary auditory cortex and Wernicke’s area

What does the occipital lobe control?

vision

What is the insula important for?

speech and motor coordination

What do commissural fibers do?

Connect hemispheres (e.g., corpus callosum)

What do association fibers do?

Connect regions within one hemisphere

What do projection fibers include?

Corticospinal (to spinal nerves) + corticobulbar (to cranial nerves)

What acoustic cue distinguishes voiced vs voiceless stops?

Voiceless stops have a later F1 onset / longer VOT

What are harmonics?

Integer multiples of the fundamental frequency (F0)

How do auditory filter widths change across frequencies?

Filter width increases as frequency decreases

What is a difference limen (DL)?

The smallest detectable change in intensity or frequency