Psychoacoustics
Digitization
Visualizations
Spectrogram
Waveform
Digital audio
Compression
MP4
MP3
Container
Bit depth
Bit rate
32 bit (float)
32 bit (int)
24 bit
16 bit = 0-65 534 (CD standard)
8 bit = 0-255
Sampling rate
96 / 192 kHz
48 kHz (standard)
44.1kHz = 44 100 Hz (CD format)
Nyquist frequency = Double of the audible range
I/O
DAC
ADC
Cognition
Auditory cortex
Neurons
14-16 billion neurons in the cortex
Cerebral cortex
The brain
Perception
Space
Time
Masking
Temporal masking
Just noticeble differences
Critical bands
Auditory filters
Loudness
Threshold of pain
>120dB
Hysteresis
Threshold of hearing
Equal-loudness contours (Fletcher-Munson)
Frequency
Just noticeable differences (JND)
Instruments
Saxophone
Sony Rollins tone
Piano
32-4186 Hz
Ranges
Ultrasound
>20,000 Hz
Audible sound
20-20,000 Hz
Infrasound
<20 Hz
Sensation
The ear
Inner ear
Middle ear
Outer ear
Auditory system
