Chapter 12: Perceiving Speech And Music Flashcards
Speech Perception
- Deals with how language sounds are perceived
- Involves relationship between perception and production
Phonemes
- smallest unit of sound that can change meaning of word
- sounds we can pronounce
Morphemes
Smallest unit of sound that provides meaning to word
International Phonetic Alphabet (IPA)
- alphabet in which each symbol stands for different speech sounds
- provides distinctive way to write each phoneme in all human languages currently in use
Producing the sounds of speech
- speech starts in the brain
- after a speaker determines what to say, the other parts of the sound production system come into play
Difference in fundamental frequency
Male (85 Hz)
Female (150-200 Hz)
Children (300+ Hz)
Vocal Folds
Aka vocal cords
- pair of membranes within larynx
Larynx
Aka voice box
- part of vocal tract that contains vocal fold
Pharynx
Uppermost part of throat
Uvula
Flop of tissue that hangs off posterior edge of soft palate
- can close off nasal cavity
Speech Production System
Influences by contraction and relaxation of throat muscles and tongue activity
Vowels
Produced with relatively unrestricted flow of air through pharynx and oral cavity
- uninterrupted, unrestricted flow
Formats
Frequency bonds with relatively high amplitude in harmonic spectrum of vowel sound
Consonants
Produced by restricting flow of air at one place of another along path of airflow vocal folds
Place of Articulation
In production of consonants, points in vocal tract at which airflow is restricted, described in terms of anatomical structures involved in creating restriction
- closing of lip
- top teeth and bottom lip
- tongue behind upper teeth
Manner of articulation
Nature of restriction of airflow in vocal tract
- whether air is fully stopped or just restricted
Voicing
Specifies whether vocal folds are vibrating or not (whether consonant is voiced or voiceless)
- whether vocal fold vibrate or not
Vowel Sounds: Production and Frequency Spectrum
Speech sound changes formant
Formants= harmonics with increased amplitude for specific sound
Sound Spectogram
Graph that includes dimensions of frequency, amplitude, and time, showing how frequencies corresponding to each sound in utterance change over time
Phonemes cannot be identified by mapping […] to specific phonemes
Phonemes cannot be identified by mapping specific frequencies to specific phonemes
Speech sounds vary, even with the same speakers, for a variety of causes
- sloppy enunciation
- speaking with mouth full
- coarticulation
Coarticulation
Influence of one phoneme on acoustic properties of another due to articulatory movements required to produce them in sequence
Variability in the Acoustics of Phonemes
Ex. The difference between “resisting arrest” and “resisting a rest”
Categorical perception of phonemes
- refers to the perception of different sensory stimuli as identical, up to a point at which further variation in the stimulus leads to a sharp change in the perception
- means that a change in some variable along a continuum is perceived not as gradual but as an instance of discrete categories
- opposite of continuous perception (no sharp changes in perception
Categorical perception and voice onset time (VOT)
Categorical perception happens when categories that observers possess influence that observer’s perception
Ex Ba vs Da
Voice Onset Time (VOT)
In production of stop consonants, interval between initial burst of frequencies and onset of voicing
*varies due to consonant place and manner of articulation
Phonemic Boundary
VOT at which stop constant transitions from being perceived as voiced —> voiceless
*when sound started vs when voicing started
McGurk effect
In perception of speech sounds, when auditory and visual stimuli conflict , the auditory system tends to compromise on a perception that shares features with both seen and heard stimuli
Knowledge takes 3 forms
- Knowledge of the grammatical rules of the language and the context in which an utterance is produced
- Knowledge about the probability of various sequences of phonemes within words or across words in the language they’re hearing
- Knowledge of the specific words that are expected in a particular situation
[…] speech is easier to perceive than […] speech
Grammatical speech is easier to perceive than ungrammatical speech
- grammatical> anomalous>ungrammatical
- ungrammatical speech is characteristic of Wernicke’s area