We are currently developing an optional add on for our LE-2 suite of SD, HD and Dual-link legalizers which will automatically control true-peak and perceptual loudness of embedded audio using ITU-R BS.1770 multi-channel loudness and true-peak algorithms.

The option will enable legalizer users to easily ensure that embedded audio content meets loudness and true-peak requirements, such as those in ATSC A/85:2009 - Recommended Practice: Techniques for Establishing and Maintaining Audio Loudness for Digital Television, in addition to the traditional legalizer role of ensuring that video levels are correct.

Here are some plots showing the loudness control effect of our automatic loudness mitigation algorithm. In each case the green line indicates the target average loudness of -24LKFS

Clip 1 before loudness processing	Clip 1 after loudness processing

Clip 2 before loudness processing	Clip 2 after loudness processing

beta testers

We are always keen to receive feedback on our product develpoments and will be looking for a number of beta sites to test out the automatic loudness mitigation option. If you are interested in being involved with the beta program, or if you have any suggestions for our automatic loudness mitigation solution, please contact labs@eyeheight.com.

useful links for audio loudness mitigation

The ASA adjudication upholding a copmplaint against ITV3 for excessive advert loudness

Article on the Broadcast Engineering website on the progress of the proposed CALM act (HR-1084) through the U.S. House of Representatives

ATSC press release covering approval of "ATSC Recommended Practice: Techniques for Establishing and Maintaining Audio Loudness for Digital Television"

Direct link to the ATSC A/85:2009 - ATSC Recommended Practice: Techniques for Establishing and Maintaining Audio Loudness for Digital Television

follow our progress on twitter.

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