Task 7 - Good vibrations... Flashcards
Sound
physical definition: sound is pressure changes in the air or other medium
Perceptual definition: sound in the experience we have when we hear
Condensation
pushing air molecules together (what a speaker does to its surrounding air) which causes a slight increase in the density of molecules near the diaphragm
Rarefaction
When the speaker diaphragm moves back in, air molecules spread out to fill in the increased space
Pure tone
occurs when pressure changes in the air occur in a pattern described by a mathematical function called a sine wave
Amplitude
the size of the pressure change
Frequency
the number of times per second that the pressure changes repeat
Decibel
(which converts the large range of sound pressure into a more manageable scale)
Fundamental frequency
the repetition rate of a complex tone
Loudness
the quality most closely related to the amplitude or sound pressure, which is also called the level of an auditory stimulus
Pitch
the perceptual quality we describe as “high” or “low” is defined as the attribute of auditory sensation in terms of which sounds may be ordered on a musical scale
Tone height
the perceptual experience of increasing pitch that accompanies increases in a tone’s fundamental frequency
Tone chroma
the letters of the notes A, B, C, D, E, F, and G (on a piano) repeat, and we notice that notes with the same letter sound similar. Because of this similarity, we say that notes with the same letter have the same tone chroma
Effect of the missing fundamental
The constancy of pitch, even when the fundamental or other harmonics are removed
Periodicity pitch
the pitch that we perceive in tones, and that has had harmonics removed
Range of hearing
we hear sound only within a specific range of frequencies
Audibility curve
indicates the threshold for hearing determined by free-field presentation (listening to a loudspeaker) versus frequency
Equal loudness curve
These curves indicate the number of decibels that create the same perception of loudness at different frequencies
Timber
the quality that distinguishes between two tones that have the same loudness, pitch, and duration, but still sound different
attack
the buildup of sound at the beginning of the tone
Decay
the decrease in sound at the end of the tone
Pinnae
the structures that stick out from the sides of the head (what we refer to when we talk about ears in a normal convo)
auditory canal
a tubelike structure about 3 cm long in adults that protects the delicate structures of the middle ear from the hazards of the outside world
Resonance
occurs in the auditory canal when sound waves that are reflected back from the closed end of the auditory canal interact with sound waves that are entering the canal – reinforces the frequency – meaning the pressure is also reinforced
Middle ear
a small cavity, about 2 cubic centimeters in volume, which separates the outer and inner ears
Ossicles
the three smallest ones in the body
Ossicles
Malleus - aka hammer. It is set into vibration by the tympanic membrane, to which it is attached, and transmits its vibrations to the incus (or anvil), which, in turn, transmits its vibrations to the stapes (or stirrup). The stapes then transmits its vibrations to the inner ear by pushing on the membrane covering the oval window
Basilar membrane
supports the organ of Corti and vibrates in response to sound
Tectorial membrane
which extends over the hair cells
Place theory of hearing
the frequency of a sound is indicated by the place along the cochlea at which nerve firing is highest – low frequencies cause maximum activity in the hair cells and auditory nerve fibers at the apex end of the basilar membrane, and high frequencies cause maximum activity in hair cells and auditory nerve fibers at the base of the membrane
Envelope of traveling wave
it has two important properties has a peak amplitude at one point on the basilar membrane
The position of this peak on the basilar membrane is a function of the frequency of the sound
Auditory masking
occurs in everyday experience any time your ability to hear a sound is decreased by the presence of other sounds
Cochlear amplifier
the action of the outer hair cells
Phase locking
the property of firing at the same place in the sound stimuli – pure tone - nerve fibre fire together when the pressure increases or decreases - auditory nerve fibres fire in synchrony with rising and falling pressure of pure tone
Temporal coding
The connection between the frequency of a sound stimulus and the timing of the auditory nerve fiber firing
Hearing loss can occur for a number of reasons
(1) blockage of sound from reaching the receptors, called conductive hearing loss;
(2) damage to the hair cells, and
(3) damage to the auditory nerve or the brain. Hearing loss due to damage to the hair cells, auditory nerve, or brain is called sensorineural hearing loss
Presbycusis
The most common form of sensorineural hearing loss, which means “old hearing
Noise-induced hearing loss
occurs when loud noises cause degeneration of the hair cells
Leisure noise
what one exposes oneself to when turning up the volume of music, or being at sports games, or working with power tools, etc.
Cochlear implant
in which electrodes are inserted in the cochlea to create hearing by electrically stimulating the cell bodies of auditory nerve fibers that are distributed along the length of the cochlea
