The International Telecommunication Union has announced new recommendations on the perceived loudness of TV broadcasts. This comes partly in response to viewers’ irritation at overly loud TV advertising.

January 18, 2010 — The ITU has proposed a new measurement technique that would enable sound technicians to measure the perceived ‘loudness’ of broadcast material, rather than just the strength of the electrical sound signal. The latter is what currently appears on a technician’s Volume Unit (VU) meter, but doesn’t directly correspond to how loud the material will seem to the viewer.

According to an ITU statement released today, many viewers wrongly suspect broadcasters of deliberately cranking up the volume during commercial breaks. In fact, the organisation says, there are various technical reasons for why this might happen. Perceived volume, it explains, is affected by various factors — including, for example, the degree of dynamic range compression (DRC) in the audio signal.

The ITU agreed the recommendations recently at its headquarters in Geneva.

The new ITU recommendations will suggest that broadcasters measure and regulate the loudness of their audio signal in accordance with a standardised “target loudness”. The draft recommendations were agreed at a meeting in November 2009 and will now be submitted to various national organisations for approval.