Language Perception

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Language Perception
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But first, a digression

• Signed versus spoken languages
• Similarities
• Both processed by same brain regions
• Both use parameters/feature
• Spoken language phonology place of articulation,
  voicing, manner
• Signed language phonology hand shape (19),
  place of articulation (12), movement (24) in ASL

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Parameters in ASL

• Hand configuration

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Parameters in ASL

• Place of articulation

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Parameters in ASL

• Movement

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ASL has morphology

• First and second person
• first person-movement toward self
• second person-movement toward other person

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ASL has morphology

• First and second person
• first person-movement toward self
• give me
• second person-movement toward other person
• give you
• Reciprocity
• pinched them versus pinched each other
• each other is movement of sign back and forth
  across body

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ASL has morphology
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But first, a digression

• Signed versus spoken languages
• Similarities
• Both processed by same brain regions
• Both use parameters/feature
• Both have dialects
• Both change over time
• There are slips of the tongue and hand

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Differences between spoken and signed languages

• Sounds of words are arbitrary (except
  onomatopoeia)
• larger words for larger things
• words sound like things
• Many signs are iconic
• dog
• Jesus
• think

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Speech Perception

• Linguists (some)
• Language processing is different from other
  cognitive skills
• There is a Language Acquisition Device
• We are born with it

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Speech Perception

• Linguists (some)
• Language processing is different from other
  cognitive skills
• There is a Language Acquisition Device
• We are born with it
• Psychologists (and psycholinguists)
• Language processing is no different that other
  cognitive skills

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Speech Perception

• Lack of invariance
• One speech sound is not the same everywhere
• Notice the formant differences in the vowels
• Physically different, yet perceived as the same

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Speech Perception

• Lack of invariance
• One speech sound is not the same everywhere
• Notice the formant differences in the vowels
• Physically different, yet perceived as the same
• Neighboring sounds affect one sound
• Different voices affect one sound
• Different speech rates affect one sound
• Levels of background noise change sound

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Speech Perception

• Lack of invariance
• One speech sound is not the same everywhere
• Stops are perceived by their influence on the
  vowel's formants, yet this influence varies by
  vowel (see d)

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Speech Perception

• Lack of invariance
• One speech sound is not the same everywhere
• How can we distinguish sounds (and the meaning
  they convey) if there is no one-to-one invariant
  feature that lets us know?
• So, maybe speech is different from other
  cognitive processes

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Speech Perception

• Categorical perception
• We can see small differences in light, color,
  tone, sound, smells. These are continuous
• When it comes to perception perception is
  categorical (ta da experiment)

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Speech Perception

• Categorical perception
• Discrimination Task Experiment'
• People hear three sounds. One of the first two is
  identical to the third. They are asked which of
  the first two matches the third.
• Results are similar to ta da study for speech
  sounds-categorical perception

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Speech Perception

• Categorical perception
• Discrimination Task Experiment
• People hear three sounds. One of the first two is
  identical to the third. They are asked which of
  the first two matches the third.
• Results are similar to ta da study for speech
  sounds-categorical perception
• For non-speech sounds the results are continuous

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Discrimination Task Experiment

• 3 kinds of synthesized sounds
• 1 Speech-like with two formants. Second formant
  varied. Difference between ba, ga is second
  formant
• 2 Only second formant transition varied. Sound
  like chirps
• 3 Second formant transition varied plus steady
  formant. Sounds like bleat
• 4 all of these backwards

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Discrimination Task Experiment

• Subjects heard three sound files. Two were
  identical and one different. They chose which one
  was different.

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Discrimination Task Experiment

• Results
• 1 Speech-like with two formants had categorical
  perception.
• 2 Only second formant transition varied had
  continuous perception
• 3 Second formant transition varied plus steady
  formant had continuous perception
• 4 all of these backwards had continuous
  perception

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Discrimination Task Experiment

• Results
• 1 Speech-like with two formants had categorical
  perception.
• 2 Only second formant transition varied had
  continuous perception
• 3 Second formant transition varied plus steady
  formant had continuous perception
• 4 all of these backwards had continuous
  perception
• So, speech perception (categorical) is different
  from other sound perception (continuous)

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Discrimination Task Experiment

• Results
• 1 Speech-like with two formants had categorical
  perception.
• 2 Only second formant transition varied had
  continuous perception
• 3 Second formant transition varied plus steady
  formant had continuous perception
• 4 all of these backwards had continuous
  perception
• So, speech perception (categorical) is different
  from other sound perception (continuous)
• But, other experiments show vowel perception is
  continuous, probably because they are very long
  and transitions due to consonants are small

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Discrimination Task Experiment

• Half of simulated speech signal to each ear.
• Second format transitions varied

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Discrimination Task Experiment

• When told to focus on chirp perception was
  continuous
• When told to focus on speech perception was
  categorical

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Motor Theory of Perception

• Speech comprehension is carried out through
  knowledge of motor skills used to pronounce
  speech

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Motor Theory of Perception

• Speech comprehension is carried out through
  knowledge of motor skills used to pronounce
  speech
• Lack of invariance problem-no clear acoustic
  relationship between acoustics and perception. To
  much variation in acoustic signal

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Motor Theory of Perception

• Speech comprehension is carried out through
  knowledge of motor skills used to pronounce
  speech
• Lack of invariance problem-no clear acoustic
  relationship between acoustics and perception. To
  much variation in acoustic signal
• Motor skills to produce sounds may be more clear
  predictors used to perceive sounds

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Motor Theory of Perception

• Speech comprehension is carried out through
  knowledge of motor skills used to pronounce
  speech
• Lack of invariance problem-no clear acoustic
  relationship between acoustics and perception. To
  much variation in acoustic signal
• Motor skills to produce sounds may be more clear
  predictors used to perceive sounds
• Claims production and comprehension are part of
  same skill, not separate

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Motor Theory of Perception

• Evidence
• McGurk effect
• In L2 acquisition people who practice
  pronunciation get better at perception

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Motor Theory of Perception

• Evidence
• McGurk effect
• In L2 acquisition people who practice
  pronunciation get better at perception
• Counterevidence
• People can't perceive allophonic variation, but
  they produce it without a problem

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What factors help us understand continuous speech

• Stress
• Listen to sentence and press button when you hear
  b
• Reaction faster in stressed syllables

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What factors help us understand continuous speech

• Stress
• Listen to sentence and press button when you hear
  b
• Reaction faster in stressed syllables
• Listen to list of words and press button when you
  hear b
• No difference between stressed and unstressed
  syllables

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What factors help us understand continuous speech

• Stress
• Listen to sentence and press button when you hear
  b
• Reaction faster in stressed syllables
• Listen to list of words and press button when you
  hear b
• No difference between stressed and unstressed
  syllables
• So, stress gives information that helps with
  sentence comprehension

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What factors help us understand continuous speech

• Speech rate
• Difference between da and ta is VOT
• Is that difference absolute? Does it change with
  speech rate?

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• da
• da
• da
• da
• ta
• ta
• ta

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What factors help us understand continuous speech

• Speech rate
• Difference between da and ta is VOT
• Is that difference absolute? Does it change with
  speech rate?
• With identical VOT, da is heard in normal speech,
  but ta in faster rate

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What factors help us understand continuous speech

• Speech rate
• Difference between da and ta is VOT
• Is that difference absolute? Does it change with
  speech rate?
• With identical VOT, da is heard in normal speech,
  but ta in faster rate
• We adapt our perception to speech rate

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What factors help us understand continuous speech

• Tone
• Is difference between high and low tone absolute?

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What factors help us understand continuous speech

• Tone
• Is difference between high and low tone absolute?
• No, women's highs are higher than men's highs.

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What factors help us understand continuous speech

• Tone
• Is difference between high and low tone absolute?
• No, women's highs are higher than men's highs.
• A person faking a higher or lower voice has high
  tones that are different
• People, like the Borg, adapt

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What factors help us understand continuous speech

• Context
• only 50 of words taken from conversation
  understood in isolation
• Top down processing

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What factors help us understand continuous speech

• Context
• only 50 of words taken from conversation
  understood in isolation
• Top down processing
• Phoneme restoration
• It was found tha the eel was on the axle.
• It was found that the eel was on the shoe.
• It was found that the eel was on the orange.

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Gating Experiment

• People hear words presented in parts
• s
• su
• sun
• At each point they are asked to guess word
• People correctly guess words before they hear all
  of the word
• E.g. soon is heard before they hear final nasal
• Because similar words like suit, say, sued, soup
  are eliminated as candidates
• Top down processing