The consultancy also estimated the number of podcast listeners will increase from 640 million in 2021 to 690 million by the end of this year.

Ximalaya Inc, one of China's biggest audio-sharing platforms, is doubling down on paid audio content services. Founded in 2012, Ximalaya provides a wide variety of audio content through which people produce, share and consume knowledge, information and entertainment.

"In the past, we poured a large amount of money into purchasing copyrights and cultivating users' habit of listening to podcasts. Currently, it still takes some time to foster their habit of paying," Yu Jianjun, co-founder and CEO of Ximalaya, said in an earlier interview.

Yu said the company has stepped up its support for excellent audio content creators, and will continue to focus on the personalized needs of people of different ages. It also plans to strengthen the production and dissemination of high-quality content.

It has signed agreements with major publishers, online literature platforms, content creators and key opinion leaders to obtain long-term copyrights in order to produce high-quality audio programs.

The Shanghai-based platform filed for an initial public offering in Hong Kong in September. The company updated its prospectus in line with the Hong Kong stock exchange's listing rules to renew its information in March.

Ximalaya's revenue reached 5.86 billion yuan in 2021, up 43.7 percent on a yearly basis, with paid subscriptions, advertisements and live broadcasts being the three major revenue streams, according to a prospectus released by the company. It had an average 268 million monthly active users last year, an increase of 24.4 percent year-on-year.

However, the company posted net losses of more than 2 billion yuan between 2019 and 2021. The losses in 2021 reached 759 million yuan, the prospectus showed.

Experts said the losses are mainly attributable to very large investments in buying copyrights, the reluctance of some users to pay for audio content and fierce competition from other video streaming and livestreaming platforms.

The company said it will continue to enrich content offerings and empower content creators as well as advance next-generation technologies, artificial intelligence and big data capabilities to further improve its operating efficiency.

In 2021, users of Ximalaya's apps spent a total of 1.74 trillion minutes listening to audio content, accounting for approximately 68.3 percent of total mobile listening time among all online audio platforms in China, according to China Insights Consultancy (CIC).

Zhang Yi, CEO and principal analyst at iiMedia Research, said there is remarkable room for growth for China's online audio industry－fueled by surging demand from users, improvements and innovation in audio technology－and growth in the way the product can be used and delivered. The number of people who are willing to spend money on paid audio content is on the rise every year, he added.

Ximalaya accounted for 28 percent of market share in the online audio segment, followed by Lizhi FM at 10 percent and Qingting FM at 4 percent, CIC reported.

"Online audio platforms monetize primarily through membership payments and advertisements. Although Chinese users are aware of paying for knowledge, there is still a long way to go before they get into this habit," said Wang Yuanya, an analyst with Beijing-based internet consultancy Analysys.

"It is difficult for these platforms to sustain operations by just relying on paid membership services," Wang said. The podcasting platforms are scrambling to get customers to listen longer in the face of mounting challenges and competition from video streaming platforms and livestreaming websites that are also striving to offer a variety of entertainment options, she said.

Wang said authorities should beef up efforts to protect intellectual property rights, while calling for audio-sharing platforms to work more closely with owners of such rights and launch more high-quality content and preferential services to increase the willingness of users to pay.

Lizhi Inc, a Nasdaq-listed Chinese platform that runs Lizhi FM and is based on user-generated content, is accelerating steps to diversify its application scenarios and integrate its online audio products into in-car intelligent entertainment systems.

"We will continue to cooperate with 'the internet of vehicles' platforms to provide a wider user base with high-quality, diverse and customized in-car audio experiences and further implement our in-car audio initiatives," said Lai Jinnan, founder and CEO of Lizhi FM. IoV connects cars and other networks to enable many vehicular data services and applications.

The company's net revenue rose 33 percent to 560.3 million yuan in the fourth quarter of 2021, primarily due to increases in the number of paying users and the average amount of user-spending on its audio entertainment, according to its financial results.

Average monthly paying users reached 497,300 in the fourth quarter, representing an increase of nearly 18 percent from 422,400 in the same period a year prior.

Its net income attributable to ordinary shareholders rose to 8.9 million yuan in the fourth quarter of last year, compared to a net loss in that category of 5.8 million yuan in the fourth quarter of 2020. Still, its net loss in that same financial category for all of 2021 stood at 127.3 million yuan. The category represents net income minus a portion for minority interests, often those with preferred stock. It is often called a key number for investors to know.

Lizhi FM said it expects to further increase user engagement and collaborate with more brands with intellectual properties to further diversify the ways its products can be used in online interactive entertainment. The company said it has also accelerated its global footprint and launched Tiya, a social networking app.

Qingting FM announced in November it had completed a new round of financing led by Digital Publishing Group Co Ltd, one of the largest digital content providers in China. The amount was not disclosed. Also participating in the financing were Xiaomi Corp, Ruiyi Investment and PV Capital. The company said that it will continue to explore new opportunities for its products in vehicle-mounted uses.

According to market consultancy Analysys, the revenue of China's online paid knowledge industry reached 23 billion yuan in 2020, while the number of users in the paid information sector was 540 million.

It said well-educated young consumers are among those most willing to pay for content on major audio-sharing and podcasting platforms, while users in fourth and fifth-tier cities are also showing surging demand for paid information services online.

"The investment in copyrighted content is crucial to enhancing user stickiness at online audio platforms," said Yu Sikun, an analyst at the Lead-Leo Research Institute, a market research provider. Stickiness means a willingness to return to a product and use it more frequently. Yu described competition in the thriving audio industry as intense, with internet companies such as Tencent, NetEase and ByteDance flocking to the market.

Yu said most of the users willing to pay for knowledge in China are middle-income earners living in the first and second-tier cities. "How the podcasting platforms stimulate users' desire to consume while maintaining the output of high-quality content is now the biggest challenge for the online audio industry."