The standard CD-quality sample rate of 44.1kHz may seem like a random choice, but it's based on the Nyquist-Shannon Sampling Theorem-a principle stating that the sample rate must be more than twice the highest frequency to be captured. Sample rate is how many times per second the sound is sampled, and bit depth is the amount of dynamic range each sample is capable of capturing. Just as analog audio is defined by the values of frequency and amplitude, digital audio has two main two parameters: sample rate and bit depth.
When these samples are played back in sequence, sounds can be accurately recreated. Since analog waveforms cannot be perfectly recreated, each sample is rounded up or down (quantized) to the nearest value. In PCM audio, signals are sampled many times per second, each sample recording the wave’s amplitude at one particular moment. Other systems, such as DTS and Dolby Digital, also exist but are more prevalent in the film and technology industries. This article will focus on Pulse Code Modulation (PCM), the most commonly used system for encoding digital audio.
0 kommentar(er)
