![]() In the Digispot system, the integral loudness of the programming item and MDB is calculated once and stored for later use, eg for normalization. This is the value you refer to when talking about the loudness of a programming item or MDL. To evaluate the loudness of a range of sound, a special technique has been developed that calculates the value of the loudness of the range, denoted by the value I and called integrated loudness. The loudness control in real time is carried out by volume indicators, there are two of them: M – Momentary and S – Short term, they differ in the measurement intervals: 0.4 sec and 3 sec, respectively. (To be mathematically precise, the relationship is not linear, but for most practical applications, the deviation from the linear relationship can be neglected.) Numerically, this relationship is linear: if the signal level increases by 6 dB, the volume will also increase by 6 LU. The volume is directly related to the level of the signal: the higher the level of the signal, the higher its volume. Loudness is measured in LUFS units, which are physically identical to decibels. This value is calculated using a special algorithm that takes into account the perception of human sound, developed by ITU \ ITU-BS.1770. Loudness is an estimate of the intensity with which the listener perceives the material. In the Digispot system, the peak indicators in the editor, property windows, and splices have the ability to display the actual sound level. The proposed procedure is reduced to increasing the sampling frequency 4 times and filtering, then the maximum amplitude is found from the interpolation of the signal obtained. ITU-R BS.1770-3 (Annex 2) defines the algorithm to calculate the “True Peak Level”. At higher signal frequencies, the peaks can be further underestimated. For example, if we have a sinusoidal signal with a frequency of 11025 Hz and we digitize it with a frequency of 44100, then the peak value of the digitized phonogram level can have a value from -3dBFS to 0dBFS, depending on the phase shift of the point of sampling on the time axis. The difference with just “Level” is that when sampling, the sample points on the time axis may not reach the maximum points of the analog signal. The term True Sound Level refers to the hypothetical amplitude level of an analog sound signal, which is an interpolation of an existing digitized soundtrack. ![]() The determination of the peak signal is combined with the simultaneous determination of its loudness, these values are always calculated together. In the Digispot system, the maximum level of the programming item and CDM is calculated once and stored for later use, eg for normalization. The signal level indicators are intended for visual observation of the current signal level in real level.Ī diagram of the signal level change over time is called a signalgram and is used to display phonograms and other sound elements in various windows of the Digispot system, for example, the splice editing window, when editing audio, etc. This level is important because it depends on how much the level can be increased, and therefore the volume of the sound, without exceeding the theoretical threshold of 0 dBFS. This level is measured in units of dBFS and is almost always negative. ![]() With regard to a programming item, MDB item, or another piece of sound, we are talking about the peak (maximum) signal level in the entire piece. The term sound level refers to the amplitude level of the sound signal. This article provides a brief explanation of the terms Sound Volume, Sound Level, Normalize, Gain, and some others, and their relationship and use in relation to the Digispot broadcast automation system. ![]()
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