Bucking a trend of declining listenership at English-language radio, Spanish-language radio has seen its audience grow 10 percent in the last decade among listeners aged 18-34.

Citing Arbitron studies, Gary Stone, Univision Radio's COO, gave a presentation today (Monday) at the Billboard Latin Music Conference showing that since 1996, English-language listenership in the demo has declined by about 10 percent -- the same proportion by which Spanish-language listenership has grown.

"We've kind of taken each other's places here," Stone told the audience at the Seminole Hard Rock Hotel in Hollywood, Fla.

That presents an opportunity for advertisers to reach audiences that are still tuning in and are statistically less likely to change the channel during commercials, said Stone.

If the 2010 census is anything like the 2000 census, said Stone, "more and more advertisers will come to the Hispanic space" as brands recognize Spanish speakers' increased affluence and cultural influence.

For Univision Radio's 13-14 million listeners, regional Mexican is the top format, followed by adult contemporary, adult hits and then Hispanic urban. To keep a younger, more tech-savvy audience from tuning out, Stone is counting on chips embedded in new cell phones that will allow radio listening via mobile, as well as his Hispanic urban stations developing podcasts.