SLHS 2010 Final Exam 2

What is the difference between lung volume and lung capacity?

Volumes—a way of partitioning off what each part of the lungs can hold

Discrete measures

Capacities—refer to the combinations of volumes that reflect physiological limits

Functional combinations of volumes

What are the differences between speech and life breathing?

Life breathing—passive process

Nose

40% of breathing cycle is inhalation, 60% is exhalation

Depends on

Body's metabolism

Body temperature

Fluid and acid-base balance

An unconscious automatic process

Rhythmic control center of medulla oblongata

Gravity pulls down rib cage

Inhalation and exhalation 1pprox... 2 seconds

Diaphragm and external intercostals relax

Elasticity returns lung tissues to normal

Torque of cartilaginous portions of ribs

Speech breathing—active process

Mouth—more efficient—less distance to lungs

10% of cycle used in inhalation, while 90% of cycle for exhalation

Depends on

Controlled release of inhaled air

Automatic nerve signals for life breathing are incorporated with voluntary nerve signals for speech breathing

You speak when you exhale

Needs more air

A conscious, controlled process

Inhalation time shorter but exhalation much longer

Vocal folds need to vibrate and produce the sawtooth wave

Air being pushed out from lungs is a more controlled air stream

Above REL, muscle control keeps air from escaping too fast

Below REL, expiration muscles contract to continue decreasing volume of thorax and lungs

What occurs during inhalation? What occurs during exhalation? How does this relate to Boyle's law?

Inhalation

Contract diaphragm

Contract external intercostals

Together, these two contractions raise the rib cage and expand the thorax

Given pleural linkage, when the thorax expands, the lungs also expand, drawing in air (Boyle's Law)

Boyle's Law

As the volume of a container increases, air pressure within the container decreases

Exhalation

Diaphragm and external intercostals relax

Internal intercostals contract

Thorax (and lungs) decrease in volume, and air is forced out

What is the one laryngeal bone? Where does it sit in the larynx?

The Hyoid Bone: A small /u-shaped bone at the top of the larynx

Attachment for tongue

How many layers do vocal folds have?

5

What is the myoelastic aerodynamic theory of phonation?

Voice production is a combination of:

Muscle (myo-)

Tissue elasticity (-elastic)

Air pressure (aero-)

Flow (-dynamic)

If given a fundamental frequency at a particular amplitude, you should be able to calculate the frequencies and amplitudes of all the harmonics.

If the fundamental is 100 Hz. At 70 dB SPL, then what are the frequencies and amplitudes of the harmonics?

Freqharm=freqfund x harmonic number

Ampharm=ampfund + [20 x log (1/harmonic number)]

Harmonic #2 will have double the frequency and half the amplitude.

2x100=200 Hz

Ampharm=70 + [20 x log(1/2)]

Ampharm=70+ [20 x-3]

Ampharm=70+ [-6]

Ampharm=64 dB

How do you find the fundamental frequency of a complex harmonic sound?

If the fundamental frequency is 50Hz, then the second would be 100Hz, the third would be 150 Hz, and so on.

How does a speaker change vocal pitch?

We can alter muscular activity to change fundamental frequency. We have conscious control over pitch

Fundamental frequency variability signals sentence type, mood, topicalization, grammatical function, etc.

Lengthening and/or tensing will increase fundamental frequency

Lengthening will decrease mass per unit length

Tensing will also increase rate of VF vibration

Relaxing will decrease fundamental frequency

Relaxing will increase mass per unit length

How does pitch differ between speakers? What are the general trends related to pitch changes due to age and sex?

Infants and toddlers= 400 Hz, shrieks= 1000 Hz (length 5-7 mm)

Older children (4-10 yrs): vocal folds lengthen and thicken (length 8 mm), causing decrease in fundamental frequency (no real sex differences)

Puberty: male larynges become longer and thicker, causing decrease in fundamental frequency. Female larynges undergo similar development, but not as extreme. Learning to adjust/control pitch (length: boys 15-25 mm; girls 12-17 mm)

Adults: Men=120 Hz (~29 mm), Women= 220 Hz (~21 mm)

In later life, male vocal folds become thinner, while female vocal folds become thicker, reducing sex differences (~145 vs. ~175 Hz)

What is the Source Filter Theory? What is the source for voiced sounds? For unvoiced sounds? What is the filter?

Explains speech and how we produce it based on the math we studied

The source- Vocal folds vibrating produces a periodic source (remember a sawtooth wave?)

The source is the output of the larynx

The Filter- The tube that the source sound goes through (remember a closed tube?)

The filter is the resonances of the vocal tract

To produce speech, we need some energy to create vibration

A source (one of the requirements for sound), and something to change it form the buzzy sawtooth to speech (e.g., a filter)

What are the different ways you can measure voice?

Vocal registers (modes of phonation)

The range of voice pitches range from <60 Hz to >1568 Hz

Pulse—low pitch

Modal—normal pitch

Falsetto—high pitch

Vocal Quality

Very broad term

Subjective

E.g., pleasant, strident, rough, raspy, shrill, clear, unpleasant, harsh, hoarse, tinny, strained...

Hyperadduction heard as tense

Hypoadduction heard as noisy or breathy

No standard frame of reference for these

Abnormal Voice Qualities

Vocal quality Is determined by the presence of noise

Breathiness—aspirated vocal tone (strong bursts of air)

Roughness—raspy vocal tone, low pitch

Hoarseness-a combination of breathy and rough qualities

Measuring Voice

Videostroboscopy

A scope that shows a video of vocal fold vibration

Can directly examine appearance, shape, size of vocal folds; look for nodules or lesions

Must be out of phase with voice to see a complete cycle of voicing

Imaging

Computed Tomography (CT)

Magnetic Resonance Imaging (MRI)

Can examine soft tissue

Electroglottography (EGG, laryngography)

A noninvasive technique that measures how tightly the vocal folds touch one another

The more the tissues are in contact, the higher the peaks

Valleys represent times when the vocal folds are separated

What are formants?

The peaks in spectral energy are called formants

Vocal source resonates at the preferred frequencies of the vocal tract

Infinite number of formants possible

5 in clear speech

The first 3 are the most important

Formants are made up of several harmonics that are amplified from resonant filtering

What are active and passive articulators?

Active Articulators-those that do most of the moving during a speech gesture

Lips

Tongue (tip/blade/body/root)

Velum (controls whether air resonates in nasal cavity)

glottis

Passive Articulators- those that do little or no moving during a speech gesture

teeth

Alveolar ridge

Palate

Velum (as a place of articulation)

Uvula

Pharyngeal wall

How does a single speaker produce the different vowels? What movement influences F1? What movement influences F2?

Across speakers, the same vowel has different formant frequencies due to differences in speaker vocal tracts

How do acoustic measurements of vowels relate to articulatory description?

Articulatory Description: How we create the sound by using our articulators

Acoustic Description: What it sounds like. What are the frequencies and amplitudes in the speech sound?

We can describe the vowels in terms of their articulatory descriptions

E.g., /i/ is a high front vowel

These articulatory descriptions perfectly predict the acoustic descriptions

/i/ is a high vowel, so it has a low-frequency first formant

/i/ is also a front vowel, so it has a high-frequency sound formant

What determines differences in formant frequencies between different speakers?

Formant 1 depends on tongue height

The volume of the pharyngeal cavity, and

How tightly the oral cavity is constricted

Formant 2 depends on tongue advancement

Length of the oral cavity

What is articulation? What is the purpose? How is that purpose accomplished?

Modifying the output of the respiratory and phonatory systems to create individual speech sounds

Manipulate resonance by altering the shape of the articulatory cavities

Purpose is to create individual speech sounds

What is the distinction between vowel production and consonant production?

If air from the glottis is allowed to pass through the articulators unimpeded, it is considered a vowel

Motion of articulators changes shape of vocal tract, influencing which frequencies are enhanced/reduced

If air is obstructed, partially or totally, in one or more places, it is considered a consonant

Direct—motion of articulators DIRECTLY influences flow of air stream (constricts/blocks)

What are manner, place, and voicing?

Articulatory Descriptors

Manner of articulation

Place of articulation

Voicing

Manner of Articulation: 11 different manners, English uses 5

Place of Articulation: 17 different places, English uses 8

Voicing

Voicing refers to whether the vocal folds are activated

[-voice] glottis is open, vocal folds are not vibrating

[+voice] vocal folds are vibrating

What are stop consonants? What are nasals? What are fricatives? What are affricates? What are approximants? What are glides?

Stop- airflow is blocked and released as a burst

Nasal- Stop with velum lowered so air passes through the nasal cavity

Fricative- Air forced through narrow channel causing turbulent airflow

Approximant-Articulators approach, but do not touch (approximate one another)

Affricate-produced with a stop-like closure with a fricative release

Glide (or semivowels) - gradual articulatory motions, vowel-like nature

How do tongue tip position and lip position play into vowel production?

High vs. low tongue position affects F1

Front vs. back tongue position affects F2

Tongue tip position affects F3

Lip position also matter somewhat

Lip position affects the overall resonance

Spreading

Rounding

Neutral

What is assimilation?

Phonemes "change" to be more compatible with surrounding phonemes

"in-" prefix in "impossible"

"in-" prefix in "intolerable"

"in-" prefix in "incorrigible"

Nasal /n/ assimilates to same place of articulation as the following phoneme

English past tense "-ed"

"walk" + "-ed" /wɔkt/

"jog" + "-ed" /dʒɔgd/

English plural "-s"

"cat" + "-s" /kæts/

"dog" + "-s" /dɔgz/

Not just in affixes-happens across word boundaries

"ten names" /tɛn:eɪmz/

"ten cards" /tɛŋkaɹdz/

"hard day" /haɹd:eɪ/

"hard book" "harb book" /haɹb:ʊk/

What is coarticulation? How does it affect speech production? How does it affect speech perception?

In conversational speech, we're producing 150-200 words a minute, or about 10 phonemes each second

Because we produce phonemes so rapidly, adjacent phonemes affect one another

They overlap in time and in frequency

The way that any phoneme is produced depends on the phonemes that come before it, and the phonemes that come after it

The positioning of the articulators at any point in time represent a compromise between where the articulators just were and where they're heading

Mushing together sounds

The articulators move toward the configuration appropriate for the upcoming phoneme, even before that sound begins

Lip rounding in "screws" /skɹuz/ vs. "script" /skɹɪpt/

Spread /s/ in "see" vs. rounded /s/ in "sue"

If you try this, you'll see that your lips are in the configuration appropriate for the upcoming sound

Coarticulation has two consequences

Lack of invariance

Because phoneme production varies in terms of surrounding context, there Is no invariant acoustic "fingerprint" for any phoneme

Lack of segmentability

The phonemes are so influenced by what comes before and after that it's impossible to separate a phoneme from surrounding ones

For speech production, coarticulation provides an efficient way to transmit a large amount of information in a relatively short time

For speech perception, it's a complication that has to be disentangled

As speaking rate increases, the phonemes get shorter and overlap more

More likely to "undershoot" articulatory targets, meaning formant frequencies don't hit targets

Some sounds may be completely deleted (elision)

Coarticulation vs. Assimilation

Coarticulation is greater at faster rates and in less careful speech

Assimilation is not dependent on rate or speaking style

What is the lack of segmentability?

The phonemes are so influenced by what comes before and after that it's impossible to separate a phoneme from surrounding ones.

What are the components of prosody?

Prosody is an interaction among intonation, stress and rhythm.

Intonation

Refers to the global pattern of pitch changes that occurs during an utterance

Typical statement—pitch starts high and falls

Typical question—pitch starts low and rises at the end

Can also signal emotion

Stress

Whereas intonation refers to pitch changes that occur over the utterance, stress refers to pitch changes within individual words.

In English, stress is conveyed via pitch, duration, and amplitude

Rhythm

Refers to the relative timing of syllables in the speech stream

In English, stressed syllables tend to have longer duration

Also, words at the end of clauses and sentences tend to have longer duration

What is the difference between conduction and transduction?

Conduction: Outer and middle ears receive acoustic energy from the environment and transmit this sound to the inner ear

Transduction/encoding: Inner ear transduces acoustic energy to electrical energy (neural impulses)

Change energy one form to another

What are the functions of the outer ear? What is the landmark between the outer and middle ear?

Functions of the Outer Ear

Conduction

Outer and middle ears receive acoustic energy from the environment and transmit this sound to the inner ear

Resonance

Our ear canal acts as a closed tube...meaning it acts as a quarter wave resonator

The smaller the ear canal, the greater resonance of higher frequencies

Infants and small children have short ear canals, therefore higher frequencies resonate

This may be why younger children are more bothered by loud high frequency sounds

This may also be why Motherese* is often used

Protection

S-shaped curve of the external auditory canal helps to keep foreign objects out of the ear

Ear wax (cerumen) collects dust and other particles that enter the ear

Localization

The ability to locate where the sound source is located (where the sound is coming from)

When we hear a sound, the two ears get slightly different acoustic versions

The brain compares information from both ears in order to determine where a sound is coming from

Outer Ear Functions

Collects/funnels sound

Protection

Resonance (amplifies certain frequencies)

Localization

ITDs

ILDs

Tympanic membrane—the transition between the outer and middle ear systems

Thin, taut piece of tissue at the end of the ear canal

Vibrates in response to sound waves that are funneled into the ear canal

Those vibrations are then transferred to the middle ear.

Be able to calculate resonant frequencies of the vocal tract and ear canal.

If the average adult ear canal is 2.5 cm long, what is the first resonant frequency (fundamental frequency) that resonates in this system?

344 m/s/4 * 0.025 =3440 Hz

What are the structures in the middle ear? What are the functions of each of these structures?

Middle Ear Functions

Mechanically links outer ear to inner ear

Amplifies sound (impedance matching)

Protects against loud sound (acoustic reflex)

Normalizes pressure

The middle ear is an air-filled space

Contains the ossicular chain

Malleus

Incus

Stapes

Also contains the eustachian tube

Functions

Impedance matching mechanisms

Protects against loud sounds (via the acoustic reflex response)

Pressure normalization

What is the function of the Eustachian tube?

Connects the middle ear to the nasopharynx

Keeps air pressure between middle and outer ears relatively equal

Normally closed, opens to allow air in or out of the middle ear cavity

What is impedance matching? Why is it necessary in the auditory system?

Impedance

Opposition to the flow of energy (e.g. resistance)

Different mediums have different impedances. Air has a lower impedance than fluid.

Energy always wants to move from high impedance to low impedance

The problem arises with conducting sound from the outer ear (air-filled low impedance) to the inner ear (fluid-filled, high impedance)

Without an "impedance matching mechanism," 99.9% of the acoustic energy from the outer ear would be lost by the time it reaches the inner ear.

There are two chambers -middle ear and

The middle ear helps to overcome the impedance mismatch

Different impedances

The Middle Ear over comes impedance mismatch by:

Surface area difference between the tympanic membrane and the oval window of the cochlea

The same amount of force is being concentrated from the tympanic membrane with a large area to the oval window with a small area, so there pressure increases by 17X at the level of the oval window! This means a boost in dB SPL by the time the signal reaches the inner ear.

Lever action of the ossicles

The malleus is longer than the incus, so the malleus moves a greater distance and the incus moves with greater force

Conical shape and flexibility by the tympanic membrane

Helps increase the pressure level by the time sound gets transmitted to the malleus

The middle ear both amplifies sound and attenuates loud sounds? What causes amplification? What causes attenuation?

Amplification: the surface area between the Tympanic Membrane and oval window of cochlea are different. There is a lever action of the ossicles; the malleus is bigger than the incus so it moves with greater force. The conical shape and flexibility of the Tympanic Membrane also aids in amplification.

Attenuation: Acoustic Reflex - the muscles connected to the ossicles contract. There is a decrease in the amount of vibration transmitted across the chain

Attenuation: Acoustic Reflex - the muscles connected to the ossicles contract

There is a decrease in the amount of vibration transmitted across the chain

What are Interaural Timing Differences and Interaural Level Differences? What are they used for?

Inter-aural Level Difference (ILD) Cues:

The brain compares amplitudes of a sound between the two ears

Primarily a result of the head shadow effect

Inter-aural Timing Difference (ITD) Cues:

The brain compares phase difference of a sound between the two ears

Determined by the distance between the two ears

What are the three chambers of the cochlea?

-Scala vestibuli

-Scala media

-Scala tympani

What is the actual organ of hearing? Where in the cochlea is it located? What structure does it rest upon? What are the sensory receptor cells called?

The Organ of Corti

Situated on top of the basilar membrane

The organ of hearing

Contains 4 rows of hair cells:

3 rows of outer hair cells

1 row of inner hair cells

What is the pattern of movement within the cochlea called? Be able to give a brief description of that pattern of movement and describe the acoustic correlates of basilar membrane movement.

Movement of the cochlear fluids causes displacement of the basilar membrane. This displacement occurs in the form of a traveling wave.

Traveling wave

Basilar Membrane vibrates in response to sound

Where the vibration occurs depends on the frequency of the sound

Movement of traveling wave along basilar membrane provides information about

Amplitude

Frequency

Amplitude of sound: Height of the traveling wave. Sound of higher intensity will induce a larger traveling wave

Frequency of sound: Where the traveling wave peaks. Low frequency sound will peak at the apex. High frequency will peak at the base

When the basilar membrane gets displaced (traveling wave occurs), the movement causes tiny cells called stereocilia to shear back and forth along the tectorial membrane

What is tonotopic organization? What happens near the base? What happens near the apex?

The cochlea is organized by frequency

Each point on the basilar membrane is tuned to a particular frequency

The base is narrow and tight, tuned to high frequencies

The apex is wide and loose, tuned to low frequencies

The basilar membrane in the cochlea is tonotopically organized by frequency.

However, not all frequencies are equally represented.

What is the difference between inner hair cells and outer hair cells? What are their functions?

Inner hair cells transduce mechanical energy from vibration into neural energy (an electrical signal)

Outer hair cells help amplify the sound (boost the traveling wave)

Be able to describe the sequence of events that occur during cochlear transduction

-Vibration of stapes pushes on oval window and displaces cochlear fluids in the scala vestibuli and scala tympani

-This movement causes basilar membrane to vibrate and traveling wave to occur

-Movement of basilar membrane causes stereocilia in the hair cells in the organ of corti to shear against tectorial membrane

-This shearing of hair cells causes the hair cells to depolarize

-When hair cells become depolarized, neurotransmitters get released triggering an action potential to auditory nerve

Where does the auditory nerve begin?

Auditory nerve fibers originate at the hair cells of the cochlea

What are the structures in the Central Auditory System (CAS)?

-Auditory nerve

-Brainstem

-Midbrain

-Auditory Cortex

CANS pathway?????

Auditory nerve

Cochlear nucleus

Superior Olivary Complex

Nucleus of the Lateral Lemniscus

Inferior Colloculus

Medial Geniculate Body of the Thalamus

Auditory Cortex

What are the structures in the auditory brainstem and midbrain?

-Cochlear nuclei

-Superior olivary complex

-Lateral lemnscus

-Inferior colliculis

-Medial geniculate body

What is the difference between afferent and efferent fibers? What information is transmitted by both?

-Afferent: send sensory signals away from the cochlea, to the brain

periphery sending information to central nervous system

-Efferent: send information away from the brain, to the cochlea

Exit:

What is the periphery vs what is central

What parts of ear are in periphery

Cochlea to brain

Just like periphery to central

What lobe in the brain is the auditory cortex located in? What is the pattern of organization in the auditory cortex called?

-The auditory cortex lies in the temporal lobe of the brain

-The pattern of organization is called tonotopic organization

What are the three aspects of a sound that are conducted to cortex? How are those three aspects transmitted and encoded by the brain?

-Frequency:

-Tonotopic organization is preserved throughout the entire auditory system, from cochlea to auditory cortex

-The brain knows which frequencies are in the sound based on where the auditory nerve fibers fire (place code)

-Intensity (Amplitude):

Intensity is encoded by how many neurons fire (small group? Large group?) and the rate at which neurons fire (fast? Slow?)

Higher intensity sounds will make large groups of neurons fire at a very fast rate

Low intensity sounds will make small groups of neurons fire at a very slow rate

-Timing:

Conveyed by when neurons fire

Timing is very important for separating detailed information about speech. (e.g., voice onset time, or when the vocal folds vibrate during speech)

How well does neural response to speech match the acoustics of speech? How is loudness related to frequency (e.g., phon contours graph/equal loudness curves)?

What the ear actually gets is an acoustic signal that is very bottom-heavy

A lot of spectral information at lower frequencies

Little spectral information at higher frequencies

Most of the time, we perceive the world as a unified bundle of sensations from multiple sensory modalities (vision, audition, touch). In other words, our perception is multimodal.

Speech is inherently multi-modal.

Human perception of amplitude depends on frequency

Our auditory system is more sensitive to sounds between 1000-5000 Hz

The range of frequencies humans can perceive is limited by the basilar membrane

Apex responds to low frequency sounds, about 20 Hz

Base responds to high frequency sounds, about 20,000 Hz

Frequency range is 20-20,000 Hz

Equal loudness curves depict the physical amplitude (dB SPL) required to make different frequencies the same loudness as a 1000 Hz tone.

How do we use bottom-up processing to perceive speech? How do we use top-down processing?

Bottom-up

cues: The actual sensory input we are receiving (vision, auditory)

when a speaker produces an utterance, s/he is actually conveying two types of information.

Linguistic properties

Language

Carry the speaker's intended message

Indexical properties

Acoustics

Carry information about the speaker's voice

Top-down cues: prior knowledge, context

What is Talker Normalization? What are the two sources of information in the speech stream? Why would we need to focus on one more than the other?

Talker Normalization

The way that any phoneme is produced depends on:

Phonetic variables (i.e., linguistic properties)

Speaker variables (i.e., indexical properties)

We need a way to link the varying realizations of different speech sounds to the underlying units (phonemes)

Through talker normalization

Strips away the indexical properties to get at the linguistic properties

Normalization of Vowels

Vowels vary in terms of formants

We may identify different vowels based on formant frequencies

BUT... remember that formants are determined by vocal tract

Men—Women—Children

Larger people have longer vocal tracts, and consequently, lower formants

The listener hears a single acoustic waveform that contains two sources of information

The absolute values of formant frequencies reveal information about speaker (speaker/indexical variables)

The relative values of formant frequencies reveal information about vowel identity (phonetic/linguistic variables)

Relative values?

Proposed transformations via ratios or logarithms

Pro—We can reduce/eliminate differences due to talker, age, gender

Con—We still get variability

Also, different vowels can have the same ratio

This is a problem...

Maybe the goal is not to strip away talker information, but rather to use it to guide perception

Perception of consonants:

In spite of difficulties, vowel perception is easier than consonant perception

Vowels tend to be voiced, have higher amplitude, clear formants, and longer durations

BUT... consonants:

Have a shorter duration

Are not always voiced

Don't always have clear formants

What is Categorical Perception? What are common tasks that show categorical perception?

Many phonemes are perceived categorically

Stops—voicing [ba]-[pa]

Stops—Place of Articulation [ba]-[da]-[ga]

Glides—F3 Transitions [ra]-[la]

Consonant Clusters—Silence "say"-"stay"

Manner—Amplitude Rise Time [∫a]-[t∫a]

Manner—Oral vs. Nasal [ba]-[ma]

But some are NOT perceived categorically

Fricative Place of Articulation [sa]-[∫a]

Stop vs. Glide Manner [ba]-[wa]

Vowels [i]-[I]

The phenomenon of categorical perception suggests that we perceive in terms of the phonetic categories

Which is learned during development

We can easily tell the difference between two phonemes from different categories, but we ignore the difference between two different versions of the same phoneme

CP of nonspeech sounds

e.g., musical intervals, not tones

CP of visual stimuli

faces, facial expressions

CP of speech by nonhuman animals

Chinchillas (adorbs!!)

Is Categorical Perception the same in all languages? The studies that compared CP in English/Spanish: What did they find? What do those results say about CP?

No, it is no the same in all languages. It depends on your language.

Spanish vs. English

Spanish speakers start voicing sooner than English speakers

This affects how they perceive the same tokens

CP cannot account for all aspects of speech perception

Relying only on bottom-up information is not the whole story

Speech is heard in the presence of information (i.e., other sounds, visual cues, language context, etc.)

We use "other" cues to process speech, too

So, what cues do we use???

Context, top-down processing, speech segmentation, multimodal integration, bootstrapping, statistics/phonotactics

What are the three basic claims of the Motor Theory? What does Motor Theory say about perception of speech vs. perception of other auditory sounds?

Perception is based on production

Even though there are no invariant acoustic features, there are invariant articulatory features that listeners can use to perceive speech.

Perception is species-specific

Since humans are the only species to produce speech, they will be the only ones to perceive it.

Perception is innate

Infants show evidence of perceiving speech well before they can produce it. They do not have to "learn" to perceive the sounds of speech.

We have two distinct sound processors

Speech-phonetic mode

Nonspeech sounds—general auditory mode

What are the three basic claims of the Auditory Theories? What do these theories say about perception of speech vs. perception of other auditory sounds?

1. Perception Is not based on production

Speech perception is like the perception of any auditory sound—General Mechanisms

2. Perception is not species-specific

Any species with a comparable auditory system should perceive speech like humans do

3. Perception may be innate

Because the auditory system is pretty much fully developed at birth, speech perception abilities may be innate

resonant frequency

speed of sound/ 4x the length