Chapter 10: Hearing, Speaking, and Making Music Flashcards
How do we hear, speak, and make music?
sound waves: stimulus for audition
functional anatomy of the auditory system
neural activity and hearing
auditory communication in nonhuman species
What is the evolution of language and music?
languages follow similar basic structural rules
people in all cultures make and enjoy music
language and music allow us to organize and to interact socially
people who can communicate their intentions to one another and to their children presumably are better parents than those who cannot
What are sound waves?
stimulus for audition
mechanical displacement of molecules caused by changing pressure
What is the visualization of a sound wave?
air molecule density is plotted against time at a single point relative to the tuning fork’s right prong
cycle: complete peak/valley, change from min/max air pressure to next min/max air level, respectively
physicists call the resulting cyclical waves sine waves
What is frequency and pitch perception?
the rate at which sound waves vibrate is measured as cycles per second, or hertz (Hz)
low frequency (low-pitched sound)
high frequency (high-pitched sound)
What is amplitude and perception of loudness?
intensity of sound is usually measured in decibels (dB)
high amplitude (loud sound)
low amplitude (soft sound)
What is complexity and timbre (perception of sound quality)?
unlike the pure tone of a tuning fork, most sounds are a mixture of frequencies
a sound’s complexity determines its timbre, allowing us to distinguish, for example, a trombone from a violin playing the same note
simple (pure tone)
complex (mix of frequencies)
What is sound wave frequency?
the number pf cycles that a wave completes in a given amount of time
measured in hertz, or cycles per second
corresponds to our perception of pitch
low pitch, low frequency: fewer cycles/second
high pitch, high frequency: many cycles/second
differences in frequency are heard as differences in pitch, each note in a musical scale has a different frequency
What is sound wave amplitude?
the intensity, or loudness, of a sound, usually measured in decibels (dB)
the magnitude of change in air molecule density
corresponds to our perception of loudness
soft sound, low amplitude
loud sound, high amplitude
What are pure tones?
sounds with a single frequency (tuning fork)
What are complex tones?
sounds with a mixture of wave frequencies
What is fundamental frequency?
the rate at which the complex waveform pattern repeats (at regular intervals)
What are overtones?
set of higher-frequency sound waves that vibrate at whole-number (integer) multiples of the fundamental frequency
What is periodicity?
the fundamental frequency repeats at regular intervals
sounds that are aperiodic, or random, we call noise
What is the perception of sound?
a rock hitting water (making waves) is much like a tree falling to the ground
the waves that emanate from the rock’s entry point are like the air pressure waves that emanate from the place where the tree strikes the ground
the frequency of the waves determines the pitch of the sound heard by the brain
the height (amplitude) of the waves determines the sound’s loudness
auditory system converts the physical properties of sound wave energy to electrochemical activity
What are properties of spoken language and music as sounds?
language and music both convey meaning and evoke emotion
left temporal lobe analyzes speech for meaning
right temporal lobe analyzes musical sounds for meaning
language facilitates communication
music helps us regulate/affect our emotions
non-speech and nonmusical noise produced at a rate of about five segments per second is perceived as a buzz
normal speed of speech is on the order of 8 to 10 segments per second (up to 30)
What are properties of language?
experience with a language helps with rapid speech, foreigners seem to speak super fast
we hear variations of a sound as if they were identical
the auditory system has a mechanism for categorizing sounds as the same despite small differences in pronunciation, makes learning foreign languages later in life more difficult
What is loudness of music?
subjective
what is very loud to some is only moderately loud to others
What is the pitch of music?
position of each tone on a musical scale, frequency of the sound wave
any pure note is perceived as the same regardless of the instrument
What is quality of music?
the timbre of a sound, regardless of pitch
you can distinguish between a trumpet and a piano sound, quality of these sounds differs
What is the functional anatomy of the auditory system?
the ear collects sound waves from the surrounding air, converts mechanical energy to electrochemical neural energy
routed through the brainstem to the auditory cortex
the auditory system is structured to decode frequency, amplitude, and complexity, some mechanism must locate sound waves in space
neural systems for sound production and analysis must be closely related
What is the evolutionary enhancement of the auditory system?
marked expansion of auditory areas in humans
What are the steps of soundwaves travelling through the auditory system?
- the pinna catches sound waves and deflects them into the external ear canal
- waves are amplified and directed to the eardrum, causing it to vibrate
- which in turn vibrates ossicles
- ossicles amplify and convey vibrations to the oval window
- vibration of oval window sends waves through cochlear fluid
- causing the basilar and tectorial membranes to bend
- which in turn cause cilia of inner hair cells to bend, this bending generates neural activity in hair cells
What is the pinna?
funnel-like external structure designed to catch sound waves in the environment and deflect them into the ear canal
What is the external ear canal?
amplifies sound waves and directs them to the eardrum which vibrates in accordance with the frequency of the sound wave
What is the middle ear?
air-filled chamber that comprises the ossicles
What are the ossicles?
bones in the middle ear
hammer (malleus)
anvil (incus)
stirrup (staples)
connects the eardrum to the oval window of the cochlea, located in the inner ear
What are the structures of the inner ear?
cochlea
basilar membrane
hair cells
tectorial membrane
What is the cochlea?
fluid-filled structure that contains the auditory receptor cells
What is the organ of corti?
receptor hair cells and the cells that support these
What is the basilar membrane?
receptor surface in the cochlea that transduces sound waves to neural activity