Chapter 11 Perceiving Speech and Music

Question 1

Phonemes

Answer 1

smallest units of sound that, if changed, would change the meaning of a word; basic sounds of a language

• > “Cat”-> “Bat”/ “Cut”/ “Cap”
• The same letter in written words often corresponds to two or more different sounds (“icicle” the two letters “I” sound quite different and represent different phonemes), or letters might correspond to no sound at all (“h” and “e” in “rhyme”)

Question 2

International Phonetic Alphabet (IPA)

Answer 2

an alphabet in which each symbol stands for a different speech sound; provides a distinctive way to write each phoneme in all the human languages currently in use.
-> Combinations of symbols and various types of accent marks

Question 3

Producing Sounds of Speech

Answer 3

Most speech sounds begin with an exhalation of air from the lungs-> trachea (windpipe)-> larynx (voice box)-> pharynx-> oral and nasal cavities -> exit body via mouth and nose

Question 4

Larynx (Voice box)

Answer 4

part of the vocal tract that contains the vocal folds

Question 5

Vocal folds (vocal cords)

Answer 5

pair of membranes within the larynx

• > can be relaxed and open, allowing air to pass silently, or can be tensed, which causes them to vibrate when air passes.
• The fundamental frequency of vocal fold vibration depends on the size and thickness of the vocal folds and the size and shape of the larynx, as well as on the current degree of contraction or relaxation of muscles in the throat.
• Vibrating vocal folds produce sounds containing harmonic frequencies in addition to the fundamental frequency.
• > Adult male: fundamental frequency of 125 Hz contains higher harmonics of 250 Hz, 375 Hz, 500 Hz, and so on, with amplitudes that tend to decrease as their frequency increases.

Question 6

Pharynx

Answer 6

Uppermost part of the throat

Question 7

Uvula

Answer 7

flap of tissue that hangs off the posterior edge of the soft plate; it can bend upward to close off the nasal cavity, directing all exhaled air into the oral cavity and out the mouth (important in the production of many speech sounds)

Question 8

Vibrations with fundamental frequencies

Answer 8

• Male: 85-180 Hz
• Females: 165-255 Hz
• Children: over 300 Hz
• Most vocalization involves changing the fundamental frequency of vocal fold vibrations.
• > Contracting or relaxing muscles in throat-> changes tension of vocal folds -> rate of vibration
• > The greater the tension, the faster the vibration, the higher the pitch

Question 9

Vowels

Answer 9

speech sounds produced with a relatively unrestricted flow of air through the pharynx and oral cavity.
-> Different vowels produced by varying the size and shape of the oral cavity.

Question 10

Consonants

Answer 10

speech sounds produced by restricting the flow of air at one place or another along the path of the airflow from the vocal folds.

Question 11

Producing Vowels

Answer 11

In order to produce different vowel sounds, a speaker has to modify the basic sound produced by his or her vocal folds, by modifying the shape of the oral cavity in order to attenuate certain harmonics more than others, with a different pattern of modification for each different vowel.
*Oral cavity with different shapes have different resonances -> frequencies are attenuated by how much

Question 12

Formants

Answer 12

frequency bands with relatively high amplitude in the harmonic spectrum of a vowel sound.

Question 13

Sound spectrogram

Answer 13

a graph that includes the dimensions of frequency, amplitude, and time, showing how the frequencies corresponding to each vowel sound in an utterance change over time.

Question 14

Producing Consonants

Answer 14

Place of articulation, Manner of articulation, Voicing

Question 15

Place of articulation

Answer 15

point in the vocal tract at which airflow is restricted, described in terms of the anatomical structures involved in creating the restriction

Question 16

Manner of articulation

Answer 16

the nature of the restriction of airflow in the vocal tract

Question 17

Voicing

Answer 17

whether the vocal folds are vibrating or not (whether the consonant is voiced or voiceless)

Question 18

Different acoustic events may all represent the same phoneme

Answer 18

• Different talkers produce sounds with different fundamental frequencies
• Dialects
• And even the same phonemes produced at different times by the same speaker can differ significantly
• Our auditory system cannot identify phonemes by simply mapping specific frequencies to specific phonemes.
• > Using the relative positions of frequencies in the context of the entire speech stream
• > Acoustic features
• > Identify the phonemes in speech
• > Listener’s knowledge of the language and understanding of the context

Question 19

Coarticulation

Answer 19

the influence of one phoneme on the acoustic properties of another, due to the articulatory movements required to produce them in sequence
*affects not only flow across the transition from one phoneme to the next, but also flow “backward”, from an upcoming phoneme to the phoneme currently being produced.

Question 20

Perceptual constancy

Answer 20

• Different sensory stimuli regularly resulting in identical perceptions
• Hear two different sounds as the same consonant

Question 21

Categorical perception

Answer 21

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.

• > Opposed to continuous perception, in which there are no sharp changes in perception as the stimulus varies.
• Research suggests that our perception of certain speech sounds is categorical rather than continuous, where the categories are different phonemes.

Question 22

Voice onset time (VOT)

Answer 22

in the production of stop consonants, the interval between the initial burst of frequencies and the onset of voicing.
*Pairs of voiceless and voiced stop consonants are always differentiated by this pattern of a relatively long VOT for the voiceless stop and a relatively short VOT for the voiced stop.

Question 23

Phonemic boundary

Answer 23

the voice onset time at which a stop consonant transitions from being mainly perceived as voiced to being mainly perceived as voiceless.

• > This transition at 30 msec VOT from mostly perceiving /ba/ to mostly perceiving /pa/
• > There are “detectors” in the auditory system tuned to respond to certain ranges of VOTs.
• > This would explain why VOTs in the range of 25-35 msec lead to uncertainty about the perception of /b/ or /p/ (/ba/ or /pa/)- both types of detectors are responding (with a similar level of response to VOTs of about 30 msec).

Question 24

McGurk Effect

Answer 24

in the perception of speech sounds, when auditory and visual stimuli conflict, the auditory system tends to compromise on apperception that shares features with both the seen and the heard stimuli; if no good compromise perception is available, either the conflict is resolved in favor of the visual stimulus or there is a conflicting perceptual experience.

Question 25

Phoneme transition probabilities

Answer 25

for any particular sequence of phonemes, the chances that the sequence occurs at the start of a word, in the middle of a word, at the end of a word, or across the boundary between two words.

Question 26

Phonemic restoration

Answer 26

a kind of perceptual completion in which listeners seem to perceive obscured or missing speech sounds.

• Based both on the auditory system’s inherent tendency toward perceptual completion of auditory stimuli (bottom-up processing) and on the listeners’ knowledge about language and context (top-down feedback)
• The restoration of fricatives was better when the masking sound was white noise, while the restoration of vowels was better when the masking sound was a pure tone.
• The frequency spectrum of fricatives resembles that of white noise, with energy distributed fairly randomly across the spectrum; in contrast, the formant structure of vowels gives them a frequency spectrum with horizontal bands of energy at just a few frequencies, which more closely resembles the spectrum of a pure tone.
• Phonemic restoration works better when the masking sound and the masked sound have similar frequency spectra than when they don’t.

Question 27

Aphasia

Answer 27

impairment in speech production or comprehension (or both) caused by damage to speech centers in the brain.

Question 28

Ventral pathway

Answer 28

meanings of words and of combinations of words

• “What” pathway
• The “meanings” of visual objects
• The identity of objects and in recognizing them

Question 29

Dorsal pathway

Answer 29

the production of speech by the motor system

• Analogous to the visual system’s dorsal “where”/”how” pathway
• Locating and acting upon visual objects

Question 30

Region in the location of the auditory cortex in both hemispheres

Answer 30

• Processes sounds of all kinds and isn’t specialized for speech
• The parts of the brain specialized for processing speech are more strongly represented in the left hemisphere than in the right hemisphere
• Simply hearing speech activates the motor centers of the brain responsible for producing speech
• A conceptual network creates representations of thoughts and ideas that flow into both pathways and provide a basis for spontaneous speech production.
• Left superior temporal sulcus- the left phonological network
• > Processing phonemes

Question 31

Pitch

Answer 31

The most fundamental dimension of music- the single characteristic that most clearly distinguishes one musical composition from another

Question 32

Octave

Answer 32

a sequence of notes in which the fundamental frequency of the last note is double the fundamental frequency of the first note.
*Notes separated by an octave are perceptually more similar than notes separated by some other interval

Question 33

Semitones

Answer 33

the 12 proportionally equivalent intervals between the notes in an octave.

• Each octave consists of 13 notes separated by 12 proportionally equivalent intervals
• The semitone intervals are perceptually equivalent to one another- that is, the difference in pitch between any two successive notes is perceived as constant even though the actual difference in fundamental frequency between successive notes increases as notes increase in frequency.

Question 34

Tone chroma (bythe color of helix)

Answer 34

differences in pitch within an octave

Question 35

Tone height

Answer 35

octave in which a tone appears, which increases from the bottom to the top of the helix

Question 36

Dynamics

Answer 36

manner in which loudness varies as a piece of music progresses.

Question 37

Rhythm

Answer 37

temporal patterning of events in a musical composition, encompassing tempo, beat, and meter.

Question 38

Tempo

Answer 38

a piece of music refers to its overall pace- that is, how fast or slow it is.

Question 39

Beat

Answer 39

equally spaced pulses that can express a fast or slow tempo

Question 40

Meter

Answer 40

temporal patterning of strong and weak pulses in the beat over time

Question 41

Timbre

Answer 41

the difference between complex sounds that have the same pitch- that is, the same fundamental frequency- and the same loudness but that don’t sound the same, like a violin and clarinet playing the same note.
*Differences in the relative amplitudes of the various overtones (or harmonic frequencies), along with differences in attack and decay (the ways in which the harmonic components begin and then fade away)

Question 42

Melody (tune)

Answer 42

a sequence of musical notes arranged in a particular rhythmic pattern, which listeners perceive as a single recognizable unit.

• Complex melodies: a series of such recognizable sequences, forming a combination that is perceived as a larger recognizable unit and may be repeated throughout a composition in various forms.
• As long as the intervals- the number of semitones higher or lower-between consecutive notes remained the same, the sequence would be perceived as the same melody.

Question 43

Transpositions

Answer 43

two versions of the same melody, containing the same intervals but starting at different notes.