Hearing Flashcards
3 main auditory percepts
Pitch - frequency of the sound wave (no of cycles per second)
Loudness - changing amplitude of sound wave
Timbre - shape of the sound wave - how is the sound being produced eg what instrument
Loudness (dB)
Has to do with sound wave pressure level
Measured in dB (a physical measure of sound amplitude) which is a logarithmic scale
Perceived Loudness
measured by comparing two tones and deciding which one sounded louder
perceieved loudness also varies with sound frequency
Pitch (Hz)
1Hz = 1 oscillation per second
metameric concept can be applied here too - same perception of pitch can be produced by lots of different sounds and waveforms
Chroma
Is doubling the frequency of a wave - aka octave
Timbre
attribute of auditory sensation in terms of which a listener can judge that two sounds, similarly presented and having the same loudness and pitch, are different
Pinna/Concha
Outer Ear
the ear that we can see
gather sound energy and focus it on eardrum
Ossicles
Middle Ear
Tympanic membrane wiggles and passes on vibration to 3 bones (malleus, incus, stapes) , from one bone to the next
Responsible for impedance matching
Impedance matching
Middle Ear
Impedance describes a mediums resistance to movement
Air has low impedance while water has high impedance
The middle ear has to amplify the signal passed from the tympanic membrane into the inner ear which is filled with fluid
Middle ear pressure boost up to 200x
Cochlea
Inner ear
Stapes attached to cochlea trasmits signal through Oval Window
Organ of Corti
Inner ear - Cochlea
The sensory organ (equivalent of retina in eye)
Contains hair cells which allow transduction (turning mechanical vibraitons to electrical signals) to take place
Vestibular nerve/membrane
Hair cells
Inner ear - Organ of Corti
Allow transductions (turning mechanical vibraitons to electrical signals) to take place
Inner hair cells
Outer hair cells
Role in active filtering/ modulating signal (if too loud, too quiet –> mechanoelectrical process)
