What is in this article?:
- Loudness management: Inconsistent audio leads to unhappy viewers.
- Understanding dialnorm and ITU-R Recommendation BS.1770
- Benefits of effective DTV loudness monitoring
Quality assurance is critical in order to be successful in a competitive broadcast market. One instance of poor-quality audio or video during an on-air broadcast can result in increased viewer complaints or viewers switching to another channel — and fewer viewers means less advertising revenue. Over the past several years, inconsistent loudness levels between advertisements and programming, in particular, have become a major source of contention for broadcast viewers, prompting regulatory bodies around the world to pass standards and legislation designed to mitigate audio loudness issues.
Advanced DTV loudness monitoring solutions promise to resolve these problems by remotely monitoring, measuring, recording and analyzing DTV streams for variations in audio loudness and ensuring that broadcasters remain compliant with audio loudness standards. This article will address the specific challenges that broadcasters face in monitoring and analyzing the audio loudness of their DTV streams according to industry specifications such as ITU-R Recommendation BS.1770, and provide effective strategies for addressing such issues.
The main challenge broadcasters must overcome in eliminating audio loudness issues is that they are receiving advertisements from a third party, whether that be a local car company, or a network, in the case of affiliate stations. Therefore, advertising content may be coming into the station with varying levels of audio. After receiving advertising (short-form) content from an outside source, broadcasters have to normalize it to ensure it possesses the same audio characteristics as the regular (long-form) programming. A broadcaster may handle hundreds of different pieces of short-form content a day, making this an extremely complicated task for station programmers to oversee.
The recommended audio loudness levels are set by standards bodies, such as the ITU-R and ATSC, and can be enforced by a geographical region’s legislative government; however, not all countries have passed legislation. The U.S. government’s Commercial Audio Loudness Mitigation (CALM) Act, passed in 2010, was the first piece of legislation designed to penalize broadcast stations and multichannel video programming distributors (MVPDs) not abiding by recommended audio loudness levels. Other regulatory bodies in Europe and the Asia-Pacific region are considering adopting similar pieces of legislation due to the increasing number of consumer complaints they receive regarding inconsistent audio levels.