According to the research released on Monday, rap and hip-hop ring tones are among the most popular type downloaded, accounting for nearly a quarter of the market.

The NPD Group, a consumer and retail research firm, said that for data compiled detailing the month of July shows that 23 percent of all ring-tone downloads fell within rap and hip-hop categories. The firm also found that 26 percent of those who downloaded ring-tones were between the ages of 13 to 17, and 22 percent between 22 to 24.

Ringtones have become very popular among consumers - especially teens and young adults who use them as personal identifiers that broadcast the type of music they want to be identified with to friends and strangers alike, according to Neil Strother, research director for mobile devices, content and services at The NPD Group.

Most buyers noted that the artist or song was the main catalyst when choosing ring-tones to purchase. Only a 24 percent mentioned price as a factor.

While price plays a role in the decision whether to download, it's only a small part of the mix, Strother said. Since younger consumers often choose clothing and other external accoutrements to help define who they are, ringtones are just another way of making a personal - and audible - mark on their environment. That's part of the reason why finding a specific song or artist is paramount among young ringtone downloaders.

Rock ring-tones were also popular, garnering 17 percent of July downloads, with pop-music next at 11 percent, and alternative 8 percent.