EBU R 128 is a recommendation for loudness normalisation and maximum level of audio signals. It is primarily followed during audio mixing of television and radio programmes and adopted by broadcasters to measure and control programme loudness. It was first issued by the European Broadcasting Union in August 2010 and most recently revised in August 2020. employs an international standard for measuring audio loudness, stated in the ITU-R BS.1770 recommendation and using the loudness measures LU (loudness units) and LUFS (loudness units referenced to full scale), specifically created with this purpose. The EBU Tech 3341 document further clarified loudness metering implementation and practices in 2016. Premise Before the adoption of , normalisation was based on the peak level of audio signals, which led to considerable loudness discrepancies between programmes and between broadcast channels. The same peak level does not necessarily produce the same loudness, because the use of dynamic range compression and limiting can increase the average level of the programme without increasing its peak level. Starting from the early 1990s through the early 2010s, both the music and the advertising industries urged the continuation of this practice to ensure that music and advertising spots became louder without exceeding the maximum permitted peak level. This phenomenon is known as the loudness war. The resulting inconsistencies and changes in loudness, especially between programmes and commercials, became a frequent cause of complaints from viewers and listeners. To help address these problems, the International Telecommunication Union (ITU) developed new algorithms to measure audio programme loudness in a manner similar to how the human ear perceives sounds and studied new methods to measure loudness over a long-term timeframe. This would allow normalising the loudness of different programs and programme contents appropriately. Development To find practical solutions for the switch from peak normalisation to loudness normalisation, the EBU Production Management Committee formed an international working group comprising sound engineers from various radio stations and broadcasting institutes. Its name, PLoud, derived from a combination of the words production and loudness. The group first developed evaluation and measurement methods to guide the development of appropriate measurement instruments in the industry. It drafted a technical document to enable broadcasters and programme producers to change their sound processing to the new recommendation, while another technical document dealt with the procedures to follow in the signal distribution. Specification Definitions To characterise the level and the dynamic range of an audio