BEIJING -- China's Bluetooth headphone market saw expansion last year, data from a recent industry report showed.

Some 85.52 million units of Bluetooth headphones were sold in China last year, increasing 7.5 percent year-on-year, according to the report from global market research firm International Data Corporation (IDC).

In breakdown, sales of true wireless earphones increased 5.1 percent year-on-year to 60.9 million units, while sales of open-ear headphones hit 6.52 million units, soaring 130.2 percent year-on-year.

The report forecasts that the open-ear headphone market in China will continue to grow this year, wireless earphones produced by cellphone brands will become cheaper, and sales channels for the headphones will diversify.