hearing, music and speech

Question 1

onset discrimination

Answer 1

Listeners can detect very brief differences in timing between the two ears. At the best frequencies (around 1000 Hz), some listeners can detect differences as small as 10 μs.

Question 2

medial superior olive (MSO)

Answer 2

A relay station in the brainstem where inputs
from both ears contribute to detection of the interaural time difference.

first place in the auditory system where input from both ears converges

firing rates of neurons hear increase in response to very brief time differences from the two ears of cats

Question 3

The properties of the ILD relevant for auditory localization are similar to those of the ITD:

Answer 3

sounds are more intense at the ear that is closer to the sound source, and less intense at the ear farther away from the source

the ILD is largest at 90 and -90 degrees. It is nonexistent at 0 degrees (directly in front) and 180 degrees (directly behind

between these two extremes, the ILD correlates with the angle of the sound source, but because of the irregular shape of the head, the correlation is less precise than it is with ITDs

Question 4

spatial hearing and blindness

Answer 4

many studies have shown that severe loss of vision can result in improved auditory perception of localization in sounds in space

region of the visual cortex is recruited to process auditory inputs when visual inputs are no longer available

Question 5

attack

Answer 5

the part of a sound during which amplitude increases (onset)

the way a complex sound begins

Question 6

decay

Answer 6

the part of a sound during which amplitude decreases (offset)

the way a complex sound ends

Question 7

auditory scene analysis

Answer 7

processing an auditory scene consisting of multiple sound sources into separate sound images

Question 8

good continuation

Answer 8

Gestalt grouping rule stating that sounds will tend to group together as continuous if they seem to share a common path, similar to a shared contour for vision.

Question 9

acoustic startle reflex

Answer 9

The very rapid motor response to a sudden sound. Very few neurons are involved in the basic startle reflex, which can also be affected by emotional state.

rapid body movement following an abrupt sound - very fast

Question 10

inattentional deafness

Answer 10

The failure to notice a fully-audible, but unexpected sound because attention was engaged on auditory stream.

Question 11

chord

Answer 11

A combination of three or more musical notes with different pitches played simultaneously

Question 12

absolute pitch

Answer 12

perfect pitch

a rare ability whereby some people are able to accurately name or produce notes without comparison to other notes

Question 13

melody

Answer 13

A sequence of notes or chords perceived as a single coherent structure.

Question 14

tempo

Answer 14

The perceived speed of the presentation of sounds.

Question 15

syncopation

Answer 15

Any deviation from a regular rhythm.

Question 16

rhythm

Answer 16

A repeated pattern of sounds comprised of strong and weak elements.

Question 17

vocal folds

Answer 17

The pair of elastic tissues that vibrate due to airflow generated by lungs, depending on how close orapart and how tense or lax they are

Question 18

phonation

Answer 18

The process through which vocal folds are made to vibrate when air pushes out of the lungs

Question 19

respiration and phonation

Answer 19

to initiate a speech sound, air must be pushed out of the lungs, through the trachea and up to the larynx.

the diaphragm flexes to draw air into the lungs, and elastic recoil forces air back out

at the larynx, air must pass through the two vocal folds, which are made up of muscle tissue that can be adjusted to vary how freely air passes through the opening between them

Question 20

three basic components of speech

Answer 20

respiration (lungs)
phonation (vocal folds)
articulation (vocal tract

Question 21

vocal tract

Answer 21

the area above the larynx

the oral tract and nasal tract combined

Question 22

articulation

Answer 22

The act or manner of producing a speech sound using the articulators—vocal tract structures including the mouth, tongue, soft palate, and jaw

manipulation of mouth structures

Question 23

resonator

Answer 23

Most objects such as musi- cal instruments and vocal tracts are resonators because, due to their shape, they increase amplitude at some fre- quencies, called resonant frequencies, compared to other frequencies.

changing the size and shape of the space through which sound passes increases and decreases energy at different frequencies

Question 24

formant

Answer 24

A resonance of the vocal tract. Formants are specified by their center frequency and are denoted by integers that increase with relative frequency.

labeled by number, from lowest frequency to highest

Question 25

categorical perception

Answer 25

For speech as well as other complex sounds and images, the phenomenon by which the discrimination of items is little better than the ability to label items.

Question 26

Loudness

Answer 26

the psychological aspect of sound related to perceived intensity or amplitude

Question 27

Pitch

Answer 27

the psychological aspect of sound related mainly to the fundamental frequency

Question 28

Timbre

Answer 28

the psychological sensation by which a listener can judge that two sounds with the same loudness and pitch are dissimilar Conveyed by harmonics and other high frequencies

Question 29

Localization

Answer 29

knowing where is the sound source

Question 30

Duration

Answer 30

length of time the stimulus is presented

Question 31

Density

Answer 31

hollow vs solid sound - if it has an echo

Question 32

Dissonance

Answer 32

how well/poorly do the notes go together Or/piano & kid running around some are dependent of history & our experiences

Question 33

Lower frequencies

Answer 33

Closer to oval window Displace basilar membrane in apex of cochlea

Question 34

Higher frequencies

Answer 34

Displace basilar membrane on base of cochlea Farther away from oval window as frequency increases

Question 35

Place code (place principle)

Answer 35

the frequency of a sound is coded by the place along the cochlear partition that has the greatest mechanical displacement High sound will have displacement closer to base

Question 36

Temporal code (frequency principle)

Answer 36

the frequency of a sounded is coded by the timing of neural firing as it relates to the period of the sound problem : neurons always fire, has a refractory period- takes time to complete AP- meaning we could hear 1000hz only

Question 37

Harmonic spectrum

Answer 37

the spectrum of a complex sound in which energy is at integer multiples of the fundamental frequency

Question 38

Fundamental frequency

Answer 38

lowest frequency of harmonic spectrum Also, the greatest common divisor of the component frequencies Perceived pitch is determined by this

Question 39

What happens when the first harmonic is missing?

Answer 39

The pitch listeners hear will still correspond to the fundamental frequency

Question 40

Missing-fundamental effect

Answer 40

perceived pitch corresponds to the fundamental frequency, even if it is missing

Question 41

Azimuth

Answer 41

the angle of a sound source on the horizon relative to a point in the center of the head between the ears- measure in degrees

Question 42

Sound localization

Answer 42

Two ears: critical for determining auditory locations That sound is closer to one ear than another Sounds arrive slightly sooner at the ear closer to the source Interaural time differences (ITDs) Interaural level differences (ILDs) Use a combination of cues ITDs:<1600Hz ILDs:>800 Hz

Question 43

Interaural time differences (ITD)

Answer 43

the difference in time between a sound arriving at one ear versus the other Know location because of which ear it arrives at first

Question 44

Interaural time differences

Answer 44

Sound travels quickly The variation there is in time it takes for a sound to reach each depends on where it comes from in space the difference in level (intensity) between a sound arriving at one ear versus the other sounds more intense at the ear closer to the source because the head partially blocks the sound pressure wave from reaching the opposite ear Different positions around the head

Question 45

Cone of confusion

Answer 45

A region of positions in space where all sounds produce the same ITDs and ILDs Happens when sound comes from directly in front or behind Same time and level intensity differences Brain may struggle to determine the actual location of a sound Perceptual phenomenon

Question 46

Head movement in sound localization

Answer 46

cones of confusion are not the only cues for determining sound sources Head movement: only one spatial location will be consistent with the ITDs and ILDs before and after the movement

Question 47

Spectral cues in sound localization

Answer 47

Directional transfer function (DTF): A measure that describes how the pinna, ear canal, head and torso, change then intensity of sounds with different frequencies that arrive at each ear from different locations in space (azimuth and elevation) Pinna have a complex shape and can funnel certain sound frequencies more efficiently than others Intensities of frequencies vary because of direction of sound Size and shape of one’s body can impact which frequencies reach the ear more quickly A measure that describes how the pinna , ear canal, head and torso change the intensity of sounds with different frequencies that arrive at each ear at different points in space le/imp. knowing live music sounds different than listening through headphones-earbuds bypass pinna

Question 48

Auditory Distance Perception

Answer 48

We are better at judging auditory direction, but not how far away something is relative intensity of the sound spectral composition of sounds relative amounts of direct vs. reverberant energy ITDs, ILDs, and DTFs do NOT provide much information about distance when sound is >1m away

Question 49

relative intensity of the sound

Answer 49

If there are 2 identical sounds we are better at perceiving - but requires us to make assumptions Bullfrog louder=closer(assumption)

Question 50

Inverse square law

Answer 50

As distance from a source increases, intensity decreases faster Intensity is proportional to the inverse of the squared distance The effectiveness of relative intensity decreases as the distance increases Sounds farther away do not seem to change direction in relation to listener- as much as nearer sounds do- like motion parallax

Question 51

spectral composition of sounds

Answer 51

Higher frequencies decrease in energy more than lower frequencies with distance (atmospheric absorption,objects)-judge signal as coming from farther away Sound absorbing qualities of air dampen high frequencies more then low frequencies So when sound sources are farther away, higher frequencies decrease in NRG more then low frequencies Farther away the sound source the more “muddier” it sounds Change noticeable only for large distances

Question 52

Relative amounts of direct vs reverberant energy

Answer 52

Sounds are some combination of this direct vs reverberant energy Relevant amount of reverberant energy decreases with distance (or direct energy decrease with distance) We are poor at knowing how far a sound is

Question 53

direct energy

Answer 53

arrives directly from source, when a sound is closer most NRG is direct

Question 54

reverberant energy

Answer 54

has bounced of services in the environment, provides a greater proportion of the total when farther away

Question 55

Tone height

Answer 55

a sound quality corresponding to the level of pitch Monotonically related to frequency

Question 56

Tone chroma

Answer 56

a sound quality shared by tones that have the same octave interval- related to the octave Each note on the musical scale (A-G) has a different chroma

Question 57

Octave

Answer 57

the interval between two sound frequencies having a ratio of 2:1 When one of two periodic sounds is double the frequency of the other, the two sounds are one octave apart Example: Fundamental frequency (C3 =130.8 Hz } x2 (C4 = 261.6 Hz }one octave x2 (C5 = 523.2 Hz }one octave

Question 58

Music and Cultural Differences

Answer 58

Some relationships between notes, such as octaves, are universal Musical scales vary widely across cultures Different notes within an octave (e.g., 7 vs 5) Estimates of intervals between notes across correspond to the music scale from their culture Six-month-old infants detect inappropriate notes in both scales but US adults only detect deviations from the Western scale

Question 59

Source segregation (auditory scene analysis)

Answer 59

processing an auditory scene consisting of multiple sound sources into separate sound images

Question 60

Spatial sound source

Answer 60

Sounds that came from the same area are treated like they are coming from the same source If sounds are moving in space they can be more easier to separate (same for if the listener moves)

Question 61

Temporal sound source

Answer 61

Sound components beginning at the same time are treated as coming from the same source Helps group harmonics into a single complex sound

Question 62

Onset sound source (common fate)

Answer 62

Gestalt grouping rule stating that the tendency of sounds to group together will increase if they begin and/or end at the same time

Question 63

Auditory stream segregation

Answer 63

the perceptual organization of a complex acoustic signal into separate auditory events for which each stream is heard as a separate event Dividing the auditory world into separate auditory objects Challenge with competing sound in the environment

Question 64

Spectrogram

Answer 64

a pattern for sound analysis that provides a three- dimensional display plotting time on the horizontal axis, frequency on the vertical axis, and intensity in colour or gray scale

Question 65

How do humans recognize speech?

Answer 65

Variability problem- when we hear speech sounds it may not be the same when we hear it next Speech is the basis of human language- connects us with other people Lower pharynx makes it easier for humans to choke on food

Question 66

Acoustic-phonetic invariance

Answer 66

There must be some constant set of acoustic features associated with each perceived phoneme- depends on prior phonemes NO: there is a lack of invariance Varies with context We perceive sounds based on relative changes in the spectrum (spectral contrast) Phoneme- smallest unit of speech, allows us to tell the difference between different words

Question 67

Coarticulation

Answer 67

the influence of one phoneme on the acoustic properties of another, due to the articulatory movements required to produce them in sequence The overlap of articulation in space and time Speech sounds are most described in terms of articulation Speed production is very fast: 10-15 consonants and vowels per second Inertia prevents tongue, lips, jaw, etc. from moving too fast Experienced talkers position tongue, etc. in anticipation of next consonant or vowel, causing coarticulation spreads out vowel and consonant information to aid understanding

Question 68

Some other sources of variation

Answer 68

Noise Sloppy pronounciation Did you go to the store?” > “Dijoo...?” Accents Gender (male: 80-200 Hz, female:150-320 Hz) Speed-rate at which we talk

Question 69

Motor theory of speech perception

Answer 69

motor processes used to produce speech sounds are used in reverse to understand the acoustic speech signal

Question 70

Evidence in favour of the motor theory

Answer 70

the McGurk Effect- auditory and visual info can differ and interfere da,ga,ba

Question 71

Evidence against the motor theory

Answer 71

Speech production is just as complex, so appealing to production to understand perception doesn’t help much Nonhuman animals can respond to human speech signals, despite not being able to produce them

Question 72

Categorical Perception

Answer 72

Manipulate sound stimuli to vary continuously from ‘bah’ to ‘dah’ to ‘gah’ Instead of perceiving gradual, continuous changes, people perceive sharp categorical boundaries between the stimuli Listeners report hearing differences between sounds only when those differences would result in different labels for the sounds

Question 73

Multiple Acoustic Cue

Answer 73

We do NOT need individual acoustic invariants to distinguish speech sounds Integrate multiple sources of information to recognize patterns E.g., visual, onset, duration, frequency, etc. Experience

Question 74

Meaning and Phoneme Perception

Answer 74

What do you hear? Phonemic restoration effect There was time to *ave... - replace with consistency of the context rave? save? wave? shave?

Question 75

How do humans recognize speech

Answer 75

Variability problem Segmentation problem

Question 76

How do we segment sound into words?

Answer 76

Look for breaks in sound stimulus? Tak by jste nevedeli kde jedno slovo konci a druhe slovo zacina Phoneme co-occurence

Question 77

Meaning and Segmentation What do you hear?

Answer 77

An American delights in simple play things Anna Mary candy lights since imp pulp lay things I’m blue song... Backwards records Context matters Relative differences matter, not absolutes Meaning, expectation, experience are powerful

Question 78

Development of speech perception Begins in utero

Answer 78

Newborns prefer hearing their mother’s voice over other women’s voices Four-day-old French babies prefer hearing French over Russian Newborns prefer hearing children’s stories that were read aloud by their mothers during their third trimester of pregnancy

Question 79

Development of speech perception Infants

Answer 79

Begin filtering out irrelevant acoustics Example: ‘r’ and ‘l’ are not distinguished in Japanese