A non-health related demo of Fluential's software.

Billionaire doctor Patrick Soon-Shiong's Nant Health is making a big investment in voice interfaces for healthcare. The company is investing $8 million in Fluential, a stealthy but longstanding company working on "of speech optimization and deep language understanding tools for mobile devices, wearables and consumer 'personal assistant' applications," according to a press release from Fluential.

The company began under the name Sehda in 2001 and originally worked on mobile translators. They deployed this technology first in the military, moving to hospital use cases in 2007. Once it began working in the healthcare space, the company changed its name and started looking into another pain point they saw in the healthcare space -- the lack of an application for health and wellness with a speech-optimized user interface.

“In the beginning there was Siri; While entertaining, Apple’s technology has not proven itself to be a practical – or even serviceable – feature for smartphone users,” Fluential Founder and CEO Farzad Ehsani said in a statement. “When voice technology learns and adapts to a user’s natural speaking habits and begins to interpret even the most ambiguous commands and inquiries successfully, then we believe it will catch on in the consumer device market.”

The company says the first consumer application for its technology will be released in Spring 2014. It will involve digital health, wellness, and weight management. In a statement, Soon-Shiong said the technology could run on not just smartphones, but also on smartwatches, Google Glass, and other wearables.

“The market potential for voice is significant, with smartwatches, Nike+ FuelBands, Google Glass, smart TVs – even cars, appliances and toys – all primed to exploit ‘voice assistant’ technologies,” he said. “Imagine a language interface so in tune with your voice that it would allow a device to effortlessly process – without the need for training, touch or type – voice-activated television navigation, the cataloging of a meal for a weight management app, or even search while shopping. To be able to tell your device, ’pull up the shopping list for my favorite low calorie chicken recipes‘ and receive the correct results would take the capabilities of any device to new heights.”

Fluential received angel funding in 2011 and holds six patents in speech recognition and natural language processing software, according to the company, with nine more pending.

Mobile health has been waiting for its own Siri for some time. MobiHealthNews ran Siri herself through some health questions in 2011 and found her bedside manner a bit lacking, although the app was able to help with a surprising number of medical-related queries. More recently, HealthTap launched Talk To Docs, a voice-activated interface for its doctor Q&A database. Meanwhile, IBM's recently announced consumer application of Watson, from WellTok, still can't speak to users out loud like Watson could on Jeopardy!.

Fluential will also face competition from Siri-maker Nuance, which has incorporated its voice recognition software into a number of electronic health records.

Soon-Shiong's investments in digital health have been varied. Nant Health owns Vitality, the makers of a smart pill bottle cap called Vitality GlowCaps. He also invested in a wireless sensor device company called Toumaz. Nant Health was previously working with iVisit on its visual recognition software LookTel back in 2011, a project which apparently spun off into Soon-Shiong's other company NantID. NantHealth raised $31 million at the start of this year.