08 Jun 23
väga põhjalik materjal.
he ear perceives level changes in a logarithmic, rather than linear, fashion. Consequently, it makes a lot more sense to measure audio signals using a logarithmic scale, rather than as straight signal voltages. In the case of professional audio signals, decibels and signal voltages are related by the formula:
Signal level in dBu = 20 x log (signal voltage / 0.775)
Semi‑pro levels can be calculated with the following formula:
Signal level in dBV = 20 x log (signal voltage)
However, the linear scale of +/- 1 is not arbitrary. For 32-bit float PCM audio, the linear scale values correspond with the actual numeric values of the samples, and for 16 / 24-bit integer formats, the integer values are scaled to a range of +/- 1.0, so regardless of the format, the +/- 1 linear scale corresponds to actual numeric values of the audio samples.
zero crossingsist.
Loga
dB are logarithmic. You just take the logarithm (base 10) of the number on the waveform plot, then multiply that by 20, to get the relative dB of a sound.