SAN MATEO, CA — A small media research firm has developed a way to bridge the gap between traditionally diverse tools that measure audience response across television, radio, computers DVDs and movie theaters. What’s more, Integrated Media Measurement Inc.’s technology takes advantage of a tool many consumers already use: a cell phone.Nielsen already has deployed the company’s technology, as have ABC, NBC and ESPN. All four companies seek integration of viewership data across a wide swath of interactive media. Because of the fragmentation of media — consumers may watch or listen to the same event in a variety of formats delivered through a variety of outlets — not only are advertisers more discerning about where they’ll place their budgets, but they also demand better and more in-depth statistics about who’s watching, when and how.

“People don’t know how to measure the multimedia world we live in, so any piece of the puzzle is helpful,” Brad Bortner, principal analyst at Forrester Research, told The Wall Street Journal.

IMMI’s technology is exceptionally helpful in finding those bits of the puzzle, clients say, because consumers typically have their cell phones with them almost 24/7.

How does the system work? IMMI embeds signal-tracking software onto the cell phones of the company’s 4,900 panelists in six major markets (New York, Los Angeles, Chicago, Miami, Houston and Denver). The software filters out background noise like phone conversations and translates into unique identifiers the signals produced by TV shows, ads, movies and songs, uploads the codes to IMMI’s database. The database cross-references the codes to create audience metrics.

One of the most helpful aspects of IMMI’s approach is that consumers can be tracked across media. For example, the cell phone software can pick up when a consumer is exposed to a movie trailer online or on TV, and then also determine if and when that same consumer actually went to see the movie. The same holds true for promos of new television series.

“We follow the same person from end to end,” IMMI Chief Executive Officer Tom Zito told The Journal.

The company currently is investigating how to expand the technology so it can track how often media advertising affects viewers’ purchases of physical items — like shampoo, toothpaste and fast food — as well as how to incorporate print advertising and outdoor advertising, neither of which employ audio.

From a consumer standpoint, IMMI’s system may be a bit more intrusive than traditional Nielsen and Arbitron audience measurement, but it’s also less of a hassle. The cell phone does all the work — no diaries to keep or buttons to push. Panelists receive other benefits as well: They are either paid $50 a month or receive free voice and data service in exchange for keeping their phones on and with them at all times.