Sensations and Perception Exam 3

Page 1

What Are We Hearing

Simple Wave- Consists of sound waves which are made up of rarefaction and compression

Rarefaction and compression involves to forward movement (compression) and backward movement (space)

Complex Wave- A wave that contains multiple frequencies

Amplitude- The size of the wave or how much energy that a wave contains or the amount of pressure that is being exerted by the sound waves

Loudness- measured in decibels which is a logarithmic curve (corresponds to both frequency and amplitude)

Doubling the loudness involves increasing the amplitude by a factor of 10

Frequency- The number of cycles or periods per second (Measured in Hz)

The more cycles per second indicates higher frequency while less cycles per second indicates lower frequencies

Pitch- Allows us to order sounds as higher or lower (corresponds with frequency)

Timbre- The unique quality of a particular sound (not having to do with pitch or loudness)

Determined by frequency and the shape of the wave

Fundamental Frequency- The lowest frequency produced by a sound

Harmonic- Multiples of the lowest frequency

Octave- Sounds like the same note but higher or lower (double the frequency)

Missing Fundamental Frequency- Removing the fundamental frequency does not change the pitch of the sound

Periodicity- The repetition of periods in a wave

Inter-harmonic- Harmonics that are between multiples of the fundamental frequency

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The Ear

Pinna- The pinna is the outer part of the ear responsible for funneling sound into the ear and detecting location of sounds

Ear Drum (Tympanic Membrane)- Moves in response to changes in air pressure; vibrates at different rates depending on the frequency of the sound waves

Lower pitch or frequency produces slower vibrations and vice versa

Lower volume or amplitude produces less dramatic vibrations

Ossicles- Three bones in the ear that are attached to the ear drum, that vibrate in response to it; sends info to the bony labyrinth

Increasing the amplitude because it needs to transfer energy from air in to water

Oval Window- Opening at the head of the cochlea that connects the middle ear to the inner ear

Cochlea- The coil shaped part of the inner ear which is filled with fluid

Organ of Corti- Sends nerve impulses along the cochlear nerve to the brain

Basilar Membrane- Bottom part of the organ of corti which vibrates and moves the hair cell's against the tectorial membrane

Tectorial Membrane- Top part of the organ of corti in which the hair cells vibrate against it to allow nerve impulses to be sent

Hair Cells- When the hair cells are pushed against the t membrane they send a nerve impulse

Tonotopic Map- Location of hair cells tell us something about pitch (rate of firing + location of firing), higher frequencies detected at base of cochlea while w frequencies are detected near apex

Phase Locking- Firing rate will match the frequency of the wave, higher the frequency the more the receptors will fire.

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Localization and Scene Analysis

Azimuth- The extension of sound from left to right

Elevation- The extension of sound top to bottom

Interaural Time Difference- The difference in time between the arrival sound in the left and right ears

Interaural Loudness Difference- The difference in loudness between the sounds in the left and right ears

Onset- Difference in the timing of the sounds

Inferior Colliculus- Contains a spatial map that locates information in space and may help integrate multisensory information

Superior Olive- Carries information about frequency and combines auditory info from both ears

Cochlear Nucleus- Tonotopic map for each ear

Auditory Cortex- Identifies complex sounds

Page 4

The Eyes in your Ears

McGurk Effect- The illusion occurs when the auditory component of one sound is paired with the visual component of another sound, leading to the perception of a third sound.

Sound-Induced Flash

Sound, Vision, and Distance

Page 5

Music

Amusia

Article on Learning Rhythms

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How do Cochlear Implants Work

Page 7

Hearing and Animals

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Examples of Relative Principles