KFAI has long been lauded — and occasionally ribbed — for serving the niche-iest of Twin Cities communities, the grassroots public-radio alternative to MPR's mainstream behemoth.

But while MPR has been holding its own with the new Personal People Meter (PPM) ratings technology, KFAI has been hit — hard.

In a letter to the station's many volunteers two weeks ago, program director Adam Mehl noted "KFAI listenership and membership are seeing their lowest levels in a long time and have been rapidly declining since 2005."

Although KFAI's slide predates PPM, and undoubtedly involves the Internet and podcasts, the recent numbers are stark. In 2005, an average of 50,000 people listened per quarter hour each week; this June, the number was 24,300.

Even worse, "time spent listening" (now known as "average time exposed," since the people meters pick up an inaudible signal in public places) has plummeted from 5 hours per week last fall during the diary era, to roughly 1 hour a week this PPM spring.

It's only my theory, but KFAI, like other shows and stations with intense fans, may have benefited from diary boosters writing in more hours than they actually listened. Personal People Meters are merciless.

Still, ratings aren't the godhead for the self-described "radio without boundaries." As Mehl's email notes, "We are not looking to simply improve Arbitron ratings ... The primary goal remains to improve community service and to serve listeners while serving our mission."

In other words, Tom Barnard will not be arriving to save the day, even though Mehl's email cites morning drive as a particular ratings weakness. (Tommy B would have to volunteer, since no KFAI host is paid.)

"We're not looking to go 'morning zoo' or anything like that," Mehl says. "Obviously, our audience is quite diverse and eclectic."

However, KFAI's numbers have sunk to the point where ratings do matter. According to executive director Janis Lane-Ewart, low listenership threatens a six-figure grant from the Corporation for Public Broadcasting, the private non-profit group that buoys radio and TV stations nationwide and around the state.

This year, the CPB contributes about $100,000, or 8 percent of KFAI's $1.3 million budget. CPB's formula factors in average quarter hour listernership divided by the coverage area population. The trends for KFAI are horrible, threatening the 2010 grant.

What to do? Mehl and Lane-Ewart aren't ready to say — not because they're being evasive, but because KFAI's board is still figuring out an audience research mechanism.

Both say the plan will likely involve focus groups of listeners and non-listeners, and some sort of a scientifically valid survey to compile unmet or underserved needs for both groups. Mehl's email mentions consulting with volunteers, "industry experts and other community radio station staff to learn what works and what doesn't" but also notes listener needs have "not been factored into the conversation as heavily as needed in the past."

I offered to funnel comments to the station, but Mehl says, "We'd be better served if people waited until this mechanism is in place. We want to have some way for people to give us information we can analyze, rather than random comments."

(Still, leave your thoughts at the end of the piece. What would make you listen to KFAI more? What isn't working right now?)

The plan is to have a plan in place within a week or two; Mehl says no changes are expected before the end of the year.