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Digital audio refers to sound that has been recorded, stored, manipulated, or reproduced using digital electronics. Unlike analog audio, which represents sound waves as continuous signals, digital audio represents these sounds as discrete numerical samples taken at regular intervals. The quality and clarity of digital audio depend on the sample rate, bit depth, and the codecs used for compression and decompression.
Digital audio is created by converting sound waves into digital signals. This process involves three main steps: sampling, quantization, and encoding. During sampling, the analog sound wave is measured at regular intervals, or samples. In quantization, each sampled value is assigned a numerical value based on its amplitude. Finally, encoding involves compressing this digital data using various algorithms to make the file size manageable without sacrificing quality. This digital file can then be stored, edited, or played back on digital devices.
The sampling rate is the number of samples of audio recorded every second and is measured in Hertz (Hz). It plays a crucial role in determining the quality of the digital audio. A higher sampling rate increases the accuracy with which the sound is captured and reproduced. The most common sampling rate for CD-quality audio is 44.1 kHz, which means that the audio is sampled 44,100 times per second.
Bit depth refers to the number of bits used to represent each audio sample. It determines the resolution of the sound by defining how many possible amplitude values each sample can have. Common bit depths are 16-bit, 24-bit, and 32-bit. A higher bit depth increases the dynamic range of the audio, allowing for more detailed sound reproduction with less noise and distortion.
Compression can be either lossy or lossless. Lossy compression, used in formats like MP3 and AAC, significantly reduces file size by removing audio information that is less audible to human ears, but this can affect sound quality. Lossless compression, used in formats like FLAC and ALAC, reduces file size without losing any audio information, preserving the original sound quality. The choice between lossy and lossless compression often depends on the required usage, storage capacity, and audio fidelity needs.