Audiophiles know that sound reproduction is improved by adding more speakers to a room and making them larger. But that won’t help make today’s increasingly slim and often tinny-sounding laptops, tablets, and phones sound good.
There is a way, however, to make small devices sound larger and better, enabling a high-quality, immersive audio experience, suggests HP Labs researcher Sunil Bharitkar a member of the Media team in HP’s Emerging Compute Lab.
“We can use software to process the audio signals on HP devices so that they approximate the spatial quality of sound that you hear in a room with a multi-loudspeaker audio system,” he says. “We call it immersive audio.”
While competing approaches offer similar processing techniques, the key to HP’s lies in applying specific audio filters and “transforms” that create natural sounding audio with a low compute complexity.
Bharitkar has been guiding an effort at HP Labs, in partnership with colleagues in HP’s Personal Systems and Print groups spearheaded by Personal Systems Chief Technologist Mike Nash, to use this research to upgrade the audio quality on HP’s mobile and desktop devices.
“Audio is an essential, and often underestimated, component of any technology experience, which is why we’re thrilled to be working in close collaboration with HP Labs to make our devices sounds second to none in the industry,” says Nash.
The team first needed to establish objective metrics against which to measure audio performance on HP devices. Based on the outcome of those measurements, they then started redesigning HP’s audio processing technology from the ground up, an effort that has included creating a novel signal topology and a unique set of audio filters.
Additionally, the researchers are applying machine learning in their audio processing topology to classify the sound content (whether it was a movie, for example, or a song). Furthermore, using machine learning it can be ensured that multiple layers of unnecessary processing are not applied where the content is identified as having already been processed, reducing the signal processing compute load and minimizing artifacts.
This is rapidly taking users towards an experience – delivered either through a device’s small speakers or a set of headphones – that faithfully reproduces the intent of its creator of any kind of audio, from a song recorded in a small studio to a Hollywood blockbuster, while consuming as little processing power as possible.
Thanks to commonalities between internationally standardized testing methodologies used for image and audio quality assessments, the HP team have been able to draw on the experience of HP’s Print Quality Evaluation group to test their improvements, assembling several panels of non-experts to evaluate their innovations..
In an effort led by HP Mobility’s Head of Software, Chris Kruger, the first iterations of HP’s new audio processing algorithms are now being packaged into the Qualcomm Snapdragon audio processing chips used in HP mobile devices. Next up: further refining the technology and adding it to HP’s consumer offerings, and towards that the Labs are working closely with Sound Research, an HP partner, for integration.