Online and satellite radio and podcasting are expected to grow through the rest of the decade, with the latter two reaching a total of 32.4 million U.S. households, a market research firm said Tuesday.

Driving adoption is consumers' desire to listen to what they want, when they want, on the device of their choosing, Forrester Research analyst Ted Schadler said.

"If radio and music executives can successfully shift their thinking to embrace new audio-delivery methods, both industries will benefit from new revenue streams and increased consumer loyalty over the next several years," Schadler said.

Forrester believes music and radio executives must adopt subscription-based models, on-demand delivery, and ad targeting strategies to succeed in the changing market environment. Major broadcasters like Clear Channel and Infinity Broadcasting, for example, should move quickly to ad- and subscription-supported online delivery, and to subscription-based programming and services to high-definition receivers to accommodate varied consumer demand.

By 2010, 20.1 million consumers will listen to satellite radio from 4.5 million last year, Forrester said. To grow steadily beyond 2010, satellite-radio providers will need to offer multi-tier subscriptions to attract the 85 percent of consumers that fall outside the early-adopter segment.

Podcasting, which is subscription-based programming that is pushed to MP3 players, is expected to reach 12.3 million households in 2010, as MP3 adoption climbs and broadband reaches 62 percent of households, Forrester said. Online radio, on the other hand, is expected to grow as portals America Online Inc., Yahoo Inc. and Microsoft Corp.'s MSN increase programming and traditional broadcasters move more programming online.

By 2010, online radio is expected to reach 30 percent of all U.S. households, and close to 50 percent of households with broadband.