IBC 2010: Linear Acoustic Monitors Audio for Mobile

An ongoing theme of the 2010 IBC show is distributing content to handheld devices, but few companies have thought about how that content will sound over handheld speakers. Producing audio for mobile TV presents a whole set of challenges that do not concern broadcasters working in stereo or even 5.1 surround sound. To ensure that the audio delivered to mobile TVs is neither harmful nor unintelligible, Linear Acoustic introduced its AERO.mobile Audio Loudness Manager at the show.

“For the reproduction of audio on a small handheld device, you have to really hone the algorithms to make sure that the intelligibility is optimized,” explained Bob Nicholas, director of business development for Linear Acoustic. “We’ve got some tests running now, and they’ve been very successful.”

Some of the challenges that arise in delivering audio for mobile TV include differences in the dynamic-range comfort zone and loudness floor. The comfort zone that is used to mix audio for viewing on TV in the home, both in stereo and 5.1 surround, is much wider than that on tiny speakers or ear buds. With background noise almost a given for the environment in which someone consumes mobile TV, the loudness floor must be relatively high. However, increasing the volume for intelligibility in soft moments may risk damaging the listener during loud ones.

To solve these challenges, among others, Linear Acoustic took its lead from solutions developed for the hearing-impaired. Those solutions focus on the most essential parts of the transmission, which is critical in targeting audio for small speakers or ear buds.

Linear Acoustic’s AERO.mobile manager uses psychoacoustic processing that enables content to remain audible in noisy environments on mobile devices. AERO.mobile accepts mono, stereo, and 5.1-channel station audio and can handle four programs simultaneously for different platform targets, giving broadcasters everything they need to deliver a satisfying experience to any mobile-TV viewer.

“With DTV, a lot more channels can be broadcast, and content can have variable revenue streams,” Nicholas said. “It’s not quite clear at the moment how they can monetize these things, but the most positive experience has to be given by the first rollout, and that’s not an easy thing to do. This is where we have applied a lot of information that we’ve gathered from our algorithm development, to try to ensure that positive first experience.”