Digitization of Sound
Digitization of sound is the process of converting
analog audio signals into digital form so that they
can be stored, processed, and transmitted by computers.
1. Introduction
Sound in the real world is analog in nature. Computers cannot process analog signals directly, so sound must be converted into digital form.
- Converts analog sound to digital data
- Used in all digital audio systems
2. Analog vs Digital Sound
Analog sound is continuous, while digital sound is represented using discrete numeric values.
- Analog: continuous waveform
- Digital: discrete samples
3. Digitization Process
- Sampling
- Quantization
- Encoding
4. Sampling
Sampling measures the amplitude of an analog signal at regular time intervals.
- Sampling rate measured in Hz
- Higher rate → better quality
5. Sampling Rate
Sampling rate defines how many samples are taken per second from the analog signal.
- CD quality: 44.1 kHz
- Professional audio: 48 kHz or higher
6. Nyquist Theorem
According to Nyquist theorem, the sampling rate must be at least twice the highest frequency present in the signal.
- Prevents aliasing
- Ensures accurate signal reconstruction
7. Quantization
Quantization converts sampled values into discrete digital levels.
- Bit depth determines resolution
- Higher bit depth → less noise
8. Encoding
Encoding represents quantized values in binary form for storage and processing.
- Binary representation
- Stored as digital audio files
9. Advantages
- Easy storage and transmission
- High noise resistance
- Supports digital processing
10. Applications
- Music CDs and streaming
- Voice recording
- Multimedia systems
- Telecommunication
Practice Questions
- What is digitization of sound?
- Explain sampling and quantization.
- What is sampling rate?
- State Nyquist theorem.
- Why is digitization important?
Practice Task
Explain with diagrams:
✔ Analog vs digital sound
✔ Sampling process
✔ Quantization levels