Loudness Assimiliator

Regulation of Loudness for any number of files

The Loudness of a particular file is lowered or raised using a direct comparison to a pink noise reference signal, in accordance with the LEQ film industry standard. To get a feeling for the Loudness Assimilator, any audio file can be taken and be edited by the LA with the 0 - setting. After that the loudness of the file is set to the reference according to LEQ(m). If the settings lead to slight clipping, then the clipping will be restored. If the settings lead to heavy clipping, then the material will not be set to the desired loudness for this section.

The internal processing algorithm is the same as in LoudnessMaximizer from CubeTec.

What is LEQ?

The TASA Standard defines trailer volume (and the upper volume limit) with a with a number that is derived using a measurement technique called LEQ(m).

LEQ(m) quantifies trailer volume as a loudness (dB) average over time using a specific filter to emphasize the mid and upper-mid frequency range. This filter was chosen to place the most emphasis on those frequencies to which the human ear is most sensitive. These are the frequencies, characteristically present in sounds like breaking glass, shrill voices, or fingernails on a chalkboard, that are most likely to be found annoying by, and generate complaints from, an audience. The specific filter used in the LEQ(m) measurement technique is similar to the CCIR curve and is defined in the TASA Standard.

Mid-range sound frequencies are not the only parameter that might result in a high LEQ(m) reading. Since the LEQ(m) measurement is integrated over the entire length of the trailer, a densely paced trailer with high volume throughout will have a higher LEQ(m) number than a slower paced trailer with more quiet spaces in between the high volume sections. To illustrate, imagine that there are two trailers that are both at the upper volume limit. Neither can be raised without exceeding the TASA Standard. One trailer has relatively high energy, high volume music throughout. The other has lower music, but more variation between the loud and soft areas. The more dynamic trailer can have louder peak volumes than the trailer that has a more compressed range. In other words, the trailer with more quiet spaces can have louder explosions and still comply with the TASA Standard. The trailer that tries to be loud throughout, however, must be relatively lower in volume, and have lower peaks, to pass. Also, because LEQ(m) emphasizes mid-range frequencies that are more irritating to the audience, the trailer that derives its volume from lower frequency bass sounds can be "louder" than the trailer that derives its volume from mid-range sounds.