Levelling and — in radio and television broadcasting Loudness

Listeners and viewers are becoming increasingly concerned over sudden variations in programme loudness. These loudness “jumps” are most apparent when zapping through European DVB television and radio channels. The loudness differences between film dialogues and highly-compressed commercial breaks (adverts) are perceived as being particularly jarring. Both under-levelling and over-levelling can be observed, resulting in level differences of more than 15 dB.