ABSTRACT
This chapter provides analog television audio, and reviews first-generation digital television (DTV) audio practice, and introduces to next-generation audio systems. It discusses a high-level overview of audio loudness measurement devices and practices. The chapter also discusses the importance of speech-based measurement and its application within the North American DTV system. It provides a high-level overview of the most essential metadata parameters required for enabling next-generation audio experiences. The chapter describes a representative set of ingest, Quality control, and content preparation processes in an immersive/interactive audio system. Television audio has traditionally kept dynamic range tightly controlled to ensure that loudness is consistent and that programs are intelligible in as many listening environments as possible. Metadata conveys information such as the loudness of a program, how many channels have been encoded, how to downmix those channels if the bitstream is decoded by a two-channel decoder, and dynamic range control values to help match the audio to the listening environment.
