sense organs: the ear the eye and other sense organs Flashcards
what is sound?
sound is a cycle of compressing and reacting molecules (think of slinky being stretched out and in)
- compression upper wave 0-180 degrees
- rarefraction lower wave 180-360 degrees
THE EAR
what are the two ways to describe a sound wave?
frequency and amplitude
what is frequency?
how often a cycle repeats itself and how often we get a full cycle
- all sound travels the same distance in given period of time
high frequencies = more squiggles and shorter wave length
low frequencies = less squiggles and longer wave length
how is frequency measured?
frequency is measured in hertz
hertz = cycles per second
what is amplitude?
how high the curves and waves go up - measures the intensity of sound
high intensity = high squiggles
low intensity = low squiggles
SOME HIGH FREQ AND HIGH AMP MIGHT NOT BE HEARABLE (how we can hear these sound but lupker cant)
how is amp/intensity measured?
measured in decibels
deca = 1/10th of something
- distance between two (10 and 20) and other two decibels (20 and 30) - not the same intensity
- goes up 10x the intensity between each pair (larger one 10x the lower one)
what is a phase?
specific point of time in a sound wave cycle
- measures where in the cycle is in the sound wave at a given point in time
what can happen when you have 2 pure tones with the same frequency? (in phase and out of phase)
in phase
- pressure changes are the same
- amplitude = sum of 2 tones
out of phase
- one reaches min at the same time the other reaches the max
- amplitude = difference between 2 tones
what is a wavelength?
distance between the first peak and the second peak (cycle)
- from max to min to max pressure
what is pitch?
whether we are expecting a high or lone not or tone
- normal ind hears 20 - 20 000 hertz
what is a pure tone?
sound that consists of one single frequency
- eg. tuning fork
what is timbre and complex sounds?
complex sounds that have additional psych properties
interaction of many diff sound waves of diff frequencies and phases that add and subtract from each other to create new sounds
- can tell diff when same note is being played on a diff instrument - each produce diff wave forms
what was Fourier’s idea about complex sounds?
any continuous periodic waveform can be represented as the sum of simple pure tones with right wavelengths, phases and amps
- eg. having diff glasses filled with diff amounts of water
ORGANS OF THE EAR