19000 hz saw

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Tags:
hz
hertz
frequency
sound
music
all
chords
sounds
noise
tone
noises
tones
audio
wave
waves
sin
sine
sinus
sinoid
rect
rectangle
square
saw
seesaw
sawed-off
triangle
triangular
triceps
non-sinusoidal
type
periodic
amplitude
pulse
pulses
pulsar
sound
sounds
heart
heartbeat
resonancy
brave

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Что это? Для чего всё это??