At the start of his career, Li Zhengjie would scour the streets, wander university campuses and even climb skyscrapers to drum up business. He quickly realized that being a freelance stenographer is hard work－even before you've landed a client.

Twelve years on, the job is still hard, but at least his income has increased.

Li's first client was a professor who paid him 160 yuan ($25) in March 2006 to record and transcribe discussions during a two-hour seminar in Beijing. Li and his wife, also a stenographer, made about 1,800 yuan a month that year, but today they can earn up to 30,000 yuan a month.

"I could barely imagine such an income when I was starting out," said Li, 36, who now leads a team of 12 stenographers covering events across the Chinese capital.

However, some in the business fear breakthroughs in artificial intelligence and smart voice-recording software is threatening their industry.

"I'm kind of worried whether this job will still exist in the years ahead," said Pan Li, who has been in the business for 12 years. She works with her friend Ma Ruijuan from a home office in Handan, Hebei province, about 400 kilometers from Beijing. They handle interviews, academic speeches, court hearings, phone surveys and celebrity appearances, charging 80 yuan an hour.

Pan, Ma and Li were all inspired to become stenographers around 2006 after spotting advertisements in local newspapers that suggested demand for such skills would soar over the following decade.

The prediction was correct, and all three have so far enjoyed decent careers. Yet as demand begins to drop due to new technologies, so are incomes.

Li mostly now works conferences, seminars and forums, but in 2006 he was receiving a lot of business from journalists who wanted quick transcriptions of their interviews.

"They'd give me their recordings and I'd usually charge them 70 or 80 yuan an hour," he said. But since 2015, that kind of work has all but disappeared. "Few are still coming to me today because they can simply use smart software and apps to produce their own transcripts," Li added.