The Spotify service has begun testing voice ads, which encourage listeners to give voice commands to navigate content related to the ad, Variety reports.

“The test is limited to a subset of U.S.-based users of Spotify’s free, ad-supported tier,” Variety reports.

Unilever’s Axe brand is one of the brands in the test. “The ad encourages listeners to check out a Spotify podcast sponsored by Unilever by saying ‘play now,'” Variety reports.

The ads only work for users who have enabled voice control, which can also be disabled at any time by the user through the ad settings.

“The test announcement comes only days after CEO Daniel Ek noted voice as a ‘critical area of growth’ for the company during Spotify’s Q1 earnings call,” Variety reports, noting that Pandora has said it will also try voice ads this year.