event identification
what is audition good for?
musical sounds
frequencies are multiples of a common fundamental frequency
Neural Coding
determining pitch; different regions of basilar membrane respond to different frequencies
Place Theory
neuron signals place by firing randomly; nearby neurons also fire but not as much.
frequency theory
neuron signals only when SPL is high (basilar membrane displaced). Firing is rhythmic
Volley/Frequency Theory
neurons take turns but all fire only on the "beat
volley frequency
below 1000 Hz roughly
place frequency
above 4000 Hz roughly
Loudness Bands
Each band measures energy in a small band on the cochlea
The sounds of music
extend across a frequency range from about 25 to 4200 hertz
Octave
The interval between two sound frequencies having a ratio of 2 to 1
Tone height
A sound quality corresponding to the level of pitch. monotonically related to frequency
Tone chroma
A sound quality shared by tones that have the same octave interval; each note on the musical scale (A-G) has a different one of these
Musical helix
Can help to visualize musical pitch
tone height and tone chroma
two characteristics of musical pitch
Musical instruments
Produce notes below 4000 Hz
5000 Hz
Listeners have great difficulty perceiving octave relationships between tones when one or both tones are greater than what?
Chords
Created when three or more notes with different pitches are played simultaneously; can be consonant or dissonant
Consonant
Have simple ratios of note frequencies
Dissonant
Less elegant ratios of note frequencies
Melody
An arrangement of notes or chords in succession; not a sequence of specific sounds but a relationship between successive notes
Rhythm
Not just in music; lots of activities have this; finger tapping, speaking, swimming
Vocal tract
The airway above the larynx used for the production of speech; includes the oral tract and nasal tract
Flexibility of vocal tract
Important in speech production
Respiration (lungs), phonation (vocal cords), articulation (vocal tract)
three parts of speech production
Initiating speech
Diaphragm pushes air out of lungs, through trachea, up to larynx
Phonation
The process through which vocal folds are made to vibrate when air pushes out of the lungs
At larynx
Air must pass through two vocal folds at what point?
Children
Small vocal folds, high-pitched voices
Adult men
Larger mass of vocal folds, low- pitched voices
Articulation
The act or manner of producing a speech sound using the vocal tract; humans can change the shape of their vocal tract by manipulating their jaws, lips, tongue body, tongue tip, and velum (soft palate)
Area above larynx
Vocal tract
Resonance characteristics
created by changing size and shape of vocal tracts to affect sound frequency distribution
formants
peaks in speech spectrum; labeled by number, from lowest to highest (F1, F2, F3)�concentrations in energy occur at different frequencies, depending on length of vocal tract
Spectrogram
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 color or gray scale
Sound
Most often described in terms of articulation
Place of articulation
a way to describe sound; (e.g., at lips, at alveolar ridge, etc.)
Voicing
a way to describe sound; whether the vocal cords are vibrating or not
English
a way to describe sound; only small sample of sounds used by languages around the world; a lot more sounds are used
Coarticulation
The phenomenon in speech whereby attributes of successive speech units overlap in articulatory or acoustic patterns
Inertia
prevents tongue, lips, jaw, etc. from moving too fast; experienced talkers position tongue, etc. in anticipation of next consonant or vowel, causing coarticulation
Computer programs
Very limited in recognizing speech because of coarticulation; perform about as well as a 2-year-old
categorical perception
people perceive sharp categorical boundaries between the stimuli
Motor theory" of speech perception
Motor processes used to produce speech sounds are used in reverse to understand the acoustic speech signal
Prenatal experience
Newborns prefer hearing their mother's voice over other women's voices
Statistical learning
Certain sounds (making words) are more likely to occur together and babies are sensitive to those probabilities
Brain damage
follows patterns of blood vessels, not brain function, so is difficult to study
PET and fMRI studies
Help to learn about speech processing in the brain
Left and right superior temporal lobes
when listening to speech, these are activated more strongly in response to speech than to nonspeech sounds
Categorical perception tasks
Listeners attempt to discriminate sounds like "bah" and "dah" while having their brain scanned
Neural responses in the brain
match behavioral responses by the subjects
Sounds that people labeled as the same
neural responses in the brain match behavioral responses by subjects; they had the same neural responses
Sounds that people labeled as different
neural responses in the brain match behavioral responses by subjects; they had different neural responses