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Flashcards in Problem 9 Deck (28)
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Acoustic signal

Refers to the patterns of pressure changes in the air

--> created by air that is pushed from the lungs past vocal cords and into the vocal tract



Structures including the

a) tongue
b) lips
c) teeth
d) jaw
e) soft palate

--> movement of theses structures alters the shape of the vocal tract



Vowels are produced by the vibration of the vocal cords

--> some vowels have more than one pronunciation
--> there are more vowel sounds than letters !

ex.: "e" sounds different in "head" and "heed"



Frequency peaks due to resonance of the vocal tract

--> our voice produces an infinite number of formants
--> formants 1+2 are responsible for vowel sounds
--> each vowel sound has a characteristic series of formants


Sound spectrogram

Indicates the pattern of frequencies and intensities over time that make up the acoustic signal


How are consonants produced ?

Consonants are produced by a constriction or closing of the vocal tract


Formant transitions

Refer tp rapid shifts in frequency preceding or following formants

--> associated with consonants

ex: "read"



Refers to the shortest segment of speech that, if changed, would change the meaning of a word

--> are defined in therms of the sounds that are used to create words in a specific language



The fact that the pronunciation of a sound in a word is affected by the sounds before and after it

ex.: "boot" vs "bat"

--> even though "b" is the same in both words, one articulates each differently


Why is coarticulation an example for perceptual constancy ?

Because be perceive the sound of a phoneme as the same even though the acoustic signal is changed by coarticulation


Why might different speakers have different acoustic signals for the same phoneme or word ?

a) slow or fast speech

b) high or low pitched voice

c) sloppy pronunciation

--> all of these variabilities are reflected in spectrograms
--> listeners must transform this info into familiar words


Categorical perception

Occurs when stimuli that exist along a continuum are perceived as divided into discrete categories


Voice onset time

Refers to the time delay between when a sound begins and when the vocal cords begin vibrating

--> property that helps us divide phonemes into discrete categories


Phonetic boundary

The point along the continuum in which the perception of speech sound changes from one category to another.

--> ex.: change form "da" to "ta"


Why is phonetic boundary an example of perceptual constancy ?

Because all the stimuli on the same side of the phonetic boundary are perceived as the same category

--> this simplifies our perception of phonemes


Why is our speech perception "multimodal" ?

Because it can be influenced by information from a number of different senses


McGurk effect/
Audiovisual speech perception

Although auditory information is the major source of information for speech perception, visual information can also exert a strong influence on what we hear


Which cortical areas are activated when perceiving speech ?

Auditory cortex: lipreading

Superior temporal sulcus: Speech perception


Phonemic restoration effect

Under certain conditions, sounds actually missing from a speech signal can be restored by the brain and may appear to be heard

--> meaningfulness makes it easier to perceive words
--> knowledge of grammar enhances effect


Speech segmentation

Perception of individual words in a conversation

--> meaning + prior knowledge are responsible for organizing sounds


Transitional probabilities

Describe the chances that one sound will follow another sound


Statistical learning

The process of learning about transitional probabilities + about other characteristics of language


Indexical Characteristics

Taking in characteristics of the speakers voice

--> carries information about the speakers

a) gender
b) age
c) place of origin
d) emotional state
e) being sarcastic or serious



Inability (or impaired ability) to understand or produce speech, as a result of brain damage


Brocas aphasia

Labored + stilted speech
--> only able to speak in short sentences

BUT: still capable of comprehension


Wernickes aphasia

1. Extremely disorganized + meaningless speech

2. Difficulty understanding what others say

BUT: fluent speech


Motor theory of speech perception

1. Hearing a particular speech sound activates motor mechanisms controlling the movement of the articulators

2. Activation of these motor mechanisms activates additional mechanisms that enable us to perceive the sound


Dual streams model

We use the ventral + dorsal pathways to perceive sounds

ventral --> gives a sound a meaning
dorsal --> sounds into movement