About one in four people, or nearly 2.5 billion, will have some level of hearing loss by 2050, according to the World Health Organization's first World Report on Hearing published March 2.
WHO also estimated that 700 million of those would require ear and hearing care unless preventive action is taken.
The report includes recommendations that countries should integrate into their health systems to address the problems.
Among low-income countries, 93 percent have fewer than one audiologist per million, according to the report. To address the shortage of ear and hearing care professionals, the report recommends integrating primary care providers into hearing care through strategies such as task sharing and training, among others.
"Integrating ear and hearing care interventions within national health plans and delivering these through strengthened health systems, as part of universal health coverage, is essential to meet the needs of those at risk of or living with hearing loss," said Dr. Bente Mikkelsen, director of noncommunicable diseases at WHO.