Sound cards
Basic sound concepts
- What is sound? Measuring sounds: decibel (dB)
- sampling rates and human hearing (20 Hz to 20 kHz)
- digital audio: DAC converters, PCM
- sampling rate: signal measured many times per second
- sampling rate: at least twice as the highest frequency
- 44.1 kHz: CD quality
- 22.05 kHz radio quality
- 11.025 kHz telephone quality
- amplitude
- 8 bits => 48 dB, 256 values for each sample
- 16 bits => 96 dB (CDs use it), 64K values for each sample
- 24 bits => 144 dB (pain threshold 125 dB), 16.8 million values