LING330: Quiz #3

Question 1

Mapping from acoustics to perception: linear or non-linear?

Answer 1

Equal changes in frequency/amplitude don’t end up as equal responses in the perceptual system

Question 2

What’s the jnd?

Answer 2

Just noticeable difference
A young healthy ear can tell the difference between a few hertz at lower decibels but once it gets over 1000 hertz you can’t tell the difference

Question 3

Scientists will often transfers raw frequency values into a logarithmic scale mathematically that better matches perceptual sensitivities. What are some of these scales?

Answer 3

Semitone scale
The bark scale
The Mel scale
The erb scale

Question 4

The Bark scale

Answer 4

Divides frequency range of human hearing into 24 bands (each step from one band to the next sounds about equal)
Logarithmic part: difference in hertz between each bark gets larger as the range gets higher but below 500hz=nearly linear
At higher frequencies, we need a bigger difference in values to perceive a change

Question 5

Normalization

Answer 5

We perceive all speech frequency/timing values as relative
Our brains use info in other parts of signal to normalize the stimulus (interpreting values relative to other values not to an external standard)
+
Same item can be heard differently when in different contexts (depends on the sounds around it)
Adjusts our expectation of what sounds should sound like using extraction of social and personal info
Explains why we can perceive consonants/vowels as the same in diff articulatory contexts

Question 6

What is VOT?

Answer 6

Voice onset time

Question 7

In a categorical perception experiment involving VOT, what was discovered?

Answer 7

Listeners=good at distinguishing sounds that are in DIFF categories, bad at distinguishing sounds in SAME category (even if acoustic difference is the same)

Question 8

What affects category boundary perception?

Answer 8

Language experience (depends on the language you speak)

Question 9

What’s special about human speech perception?

Answer 9

Processed by diff cognitive system than other acoustic data like music and non-linguistic sounds
**weakened when found that other domains use categorization such as visual perception and animals also do this

Question 10

Cue integration

Answer 10

Brain takes multiple pieces of info that it receives and uses its perception of them to create a single object (ex: phoneme)
**pieces of info separated in time and extracted at diff points in auditory pathway when listening to words or sentences

Question 11

What role does the auditory cortex play?

Answer 11

Puts pieces of phonetic info back together again after they’ve been extracted by other parts of the brain

Question 12

Describe top-down processing

Answer 12

Acoustic cues come into brain from the BOTTOM UP but
Predictions made in brain for speech processing are TOP DOWN
Brain is PRIMED to hear certain sounds/words in a specific context
Responsible for PHONEME RESTORATION
**proof of word-level prototypes are stored

Question 13

Phoneme restoration

Answer 13

Experiment where sound segment is replaced by a non-speech sound; sound segment will still be perceived even if missing because it is obvious through context
**proof of word-level prototypes are stored

Question 14

What are prototype models?

Answer 14

Traditional answers of “to what linguistic representation is the speech signal mapped?” are based on this
Assumes that ideal version of a linguistic unit is stored in memory
Accounts for categorical perception
Diffs in detail are not noticed unless they cause a mapping to diff stored representation
Abstract/idealized version of linguistic unit stored in memory, incoming symbol checked against it
Detailed info discarded

Question 15

How do feature detectors work? (Prototype models)

Answer 15

Pick up distinct acoustic events and match them to segment characteristics (different between languages)
Segments identified -> assembled into words
Cues before certain segments that help us predict
Proposition that units of perception=DEMI SYLLABLES (CV or VC combos) or WHOLE SYLLABLES

Question 16

Motor theory of speech perception

Answer 16

Against view of stored word-level prototypes
Argue that units of perception are articulatory gestures themselves
Sound patterns=medium by which we hear but articulatory movements that caused the sounds=OBJECTS HEARD
Learn ability=mirror neurons (same neurons fired when seeing someone doing something and when doing it yourself)

Question 17

How do the motor theory of speech perception theorists explain how it is learned?

Answer 17

Babies listen to their own utterances which teaches them what ACOUSTIC PATTERNS go with what SPEECH GESTURES
NEURAL LINK between auditory and motor cortex

Question 18

Arguments against motor theory of speech perception

Answer 18

• we can perceive speech that no vocal tract could create (sine wave speech)
• brain injury affects production and perception separately

Question 19

Prototype models vs exemplar models

Answer 19

Prototype: assume that match to linguistic unit is made -> detailed info in the signal=thrown out and speech processing continues on abstract level

Exemplar models: very detailed memory traces are retained and referenced
Episodic traces=linked together at multiple levels into multi-dimensional groupings
Detailed and specific, not abstract like prototype model
Categorization=label + details of specific instances
New tokens are compared against stored tokens, not an abstract ideal

Question 20

How categorization differs in exemplar models

Answer 20

Stimulus SIMILAR to exemplar: faster and more accurate categorization; category label is reinforced + boundaries sharpen

Stimulus NOT similar: category may shift -> language change

Question 21

Support for exemplar models

Answer 21

• supported by psycholinguistic research that says details do matter + connections exist at multiple levels
• consistent with frequency effects (how often you hear a sound makes a difference)
• priming

Question 22

Commonly used method for conducting a discrimination experiment

Answer 22

ABX or oddball task
Stimuli A, B and X
A and B=always diff stimuli 
X=always matches A or B
Listener has to indicate whether X matches A or B

Question 23

What are humans better at: discrimination or identification?

Answer 23

Neither (same)

Question 24

Perception differences between plosives and vowels

Answer 24

Plosives: categorically perceived (plosives=short/dynamic)

Vowels: perceived on a continuum (vowels=relatively long but when shortened, perceived categorically lol plosives)

Question 25

Two response measures that show that listeners do perceive diffs among members of the same category

Answer 25

Reaction time: used as a measure of amount of processing (the more ambiguous a stimulus, the more time it takes for a subject to process it + time to perform a certain reaction will be longer)

Goodness rating: shows how good an example of a given item is, as judged by a subject

Question 26

Technique to test babies on speech perception (specifically plosives)

Answer 26

High amplitude sucking paradigm (HAS)
Babies sucking rate INCREASES when presented with stimuli that is new/unfamiliar to them
Pacifier wired to a transducer
When sucking rate decreases=habituation

Question 27

Infant perception results suggest what?

Answer 27

Suggests that categorical perception observed in adults is NOT due to linguistic experience throughout life, rather PRESENT AT BIRTH

Question 28

Two competing hypotheses of speech is special debate (whether or not human speech perception uses mechanisms that evolved especially for processing speech)

Answer 28

Special mechanism account (SMA): speech perceived as result of specialized, speech-specific mechanisms that exist only in humans

General mechanism account (GMA): speech perception based on general auditory and cognitive mechanisms and doesn’t require innate speech-specific processes

Question 29

Evidence in the “speech is special” debate

Answer 29

1- perception of speech and non-speech sounds by humans (non-speech can be created to resemble speech in amplitude and frequency; tests claim that speech-specific mechanisms ARE required)

2- perception of speech in humans vs animals

Question 30

The study of non-native speech perception

Answer 30

Cross-language speech perception

Question 31

Two major models of L2 phonetic category acquisition

Answer 31

1- the perceptual assimilation model: model of non-native speech perception by naive listeners that aren’t familiar with the target language (non-native contrasts perceived in terms of how similar they are to phonological categories in native lang)

2- speech learning model: focuses on attainment of L2 pronunciation and says that errors in L2 production have perceptual basis; doesn’t specify whether relation between sounds in L1 and L2 is acoustic or auditory in nature
SLM predicts that the process of equivalence classification prevents L2 learners from making a new category for similar (not new) sounds (affects pronunciation)

Question 32

Perceptual difficulty that adult listeners has in L2 due to what factors?

Answer 32

• L1/L2 phoneme inventories
• specific acoustic cues to mark phoneme distinctions
• allophonic distribution of phonetic segments in L1 and L2
• age
• amount of exposure to L2
• quality of L2 input
• how much they use the L1 and L2
• *perceptual system=plasticity that allows for phonetic categories to be changed

Question 33

Five factors that affect perception

Answer 33

1- non linearity 
2- normalization 
3- cue integration
4- processing
5- language exposure

Question 34

Is mapping of acoustic signal and/or perception linear?

Answer 34

Mapping of acoustic signal=linear
Perception=non linear
Equal changes in frequency (pitch) and amplitude (loudness) are not matched by equal responses in our perceptual system

Question 35

Are auditory frequency scales logarithmic?

Answer 35

Yes!
200 hz is twice as high as 100 hz
1 octave is also perceived as twice as high
But a two octave increase (ex: double the pitch/performed frequency) = 4 x f0!

Question 36

Perceptual scales of loudness vs duration

Answer 36

Loudness: we perceive sounds between 2-4 KHz better than very high or very low pitch sounds; phons/sones

Duration: words in isolation tend to be longer than those in connected speech; perceived as same duration

Question 37

In terms of VOT, categorical perception means that English listeners switch from categorizing sound as [d] to [t] when?

Answer 37

At a specific point!

Question 38

Special mechanism vs general mechanism account

Answer 38

Special mechanism account: speech perception is because of speech specific mechanisms

General mechanism account: speech perception is based on general auditory and cognitive mechanisms

Question 39

Testing non-human perception on chinchillas

Answer 39

Electric shock at one end of continuum 
Drinking water at other end
Remaining members of continuum added 
Categorical perception similar to humans 
**also conducted on monkeys and quails

Question 40

Conclusions about basic speech perception

Answer 40

It’s not only in humans
It’s not speech specific
Result of general auditory mechanisms

Question 41

2 theories of perception in L2

Answer 41

Sounds inventories of L1 and L2 affect which within-category distinctions are made
1- SLM (speech learning model)
2- PAM (perceptual assimilation model)

Question 42

PAM (perceptual assimilation model)

Answer 42

-non native contrasts perceived in terms of gestural similarity to L1 phonological categories
-difference in leaning new vs similar phones:
Single category vs two category assimilation
Categorized (perceived as instances of L1) and Uncategorized (nothing like L1)

Question 43

SLM (speech learning model)

Answer 43

Focused on articulation
Doesn’t specify articulation vs acoustics perception
New vs similar phones
English speakers learn French [y] but not the dental [t]