audio test
https://developer.mozilla.org/ko/docs/Web/HTML/Element/audio
https://developer.mozilla.org/en-US/docs/Web/API/AudioContext/AudioContext
https://developer.mozilla.org/en-US/docs/Web/API/AnalyserNode/AnalyserNode
https://developer.mozilla.org/en-US/docs/Web/API/WaveShaperNode
https://developer.mozilla.org/en-US/docs/Web/API/BiquadFilterNode
https://pks2974.medium.com/web-audio-%EA%B0%84%EB%8B%A8-%EC%A0%95%EB%A6%AC%ED%95%98%EA%B8%B0-952a19d6aa45
load at Local file
control
play
pause
mute
myAudio.volume
setting
connect BiquadFilter
On
BiquadFilter.type
lowpass
highpass
bandpass
lowshelf
highshelf
peaking
notch
allpass
biquadFilterNode.gain.value
biquadFilterNode.frequency.value
biquadFilterNode.Q.value
gainNode.gain.value
waveShaperNode.curve
waveShaperNode.oversample
none
2x
4x
time-domain
frequency