San Bruno, Calif.-based Apptera said it has raised $10.5 million in an undisclosed round of venture funding. Investors in the round include: Lightspeed Venture Partners, Alloy Ventures, and Walden International. The money will go towards investing in the company’s audio and visual mobile advertising network. Advertisers can use the company’s ad platform and technology to insert audio advertisements within a call, and then follow-up with a visual ad. For instance, a person may call in to a movie phone service to hear when the latest movie is playing. An audio ad for a nearby restaurant may play, and if a person is interested, they can request a coupon or driving directions by text message. The company can also add an audio component to a text ad, which allows a person to click to call from an SMS. Henry Vogel, Apptera’s president and CEO: “A lot of people are thinking about mobile advertising as the ability to send a SMS, or a WAP banner, but you are constrained in the richness and whether people have a data plan, but every device absolutely has a phone.” Founded in 2001, Apptera already has customers such as AT&T’s 1-800-YellowPages, AOL’s Moviefone, MovieTickets.com, Bank of America’s ATM locator, SaveMart supermarkets, MLB.com, RadioShack, GSI Commerce and SayNow’s social music service. The company declined to say how much money it previously raised, and said it has fewer than 100 employees.