From your mouth to your screen, transcribing takes the next step

Sam Liang longs for his mother and wishes he could recapture the things she told him when he was in high school.

“I really miss her,” he said of her death in 2001. “Those were precious lifetime moments.”

Liang, who is the CEO and co-founder of Otter.ai, a Los Altos startup, has set out to do something about that in the future. His company offers a service that automatically transcribes speech with high enough accuracy that it is gaining popularity with journalists, students, podcasters and corporate workers.

Improvements in software technology have made automatic speech transcription possible. By capturing vast quantities of human speech, neural network programs can be trained to recognize spoken language with accuracy rates that in the best circumstances approach 95%. Coupled with the plunging cost of storing data, it is now possible to use human language in ways that were unthinkable just a few years ago.

Liang, a Stanford-educated electrical engineer who was a member of the original team that designed Google Maps, said that data compression had made it possible to capture the speech conversation of a person’s entire life in just two terabytes of information — compact enough to fit on storage devices that cost less than $50.

The rapid improvement in speech recognition technology, which over the past decade has given rise to virtual speech assistants such as Apple’s Siri, Amazon’s Alexa, Google Voice, Microsoft Cortana and others, is spilling into new areas that are beginning to have a significant impact on the workplace.

These consumer speech portals have already raised extensive new privacy concerns. “Computers have a much greater ability to organize, access and evaluate human communications than do people,” said Marc Rotenberg, president and executive director of the Electronic Privacy...