IF YOUR FRIENDLY local radio station's programming sounds different these days, it may be the result of sensible decisions by the Federal Communications Commission and the Supreme Court to stop government from determining what kinds of words and music a station may or may not air. So far, at least as we hear, there hasn't been any dramatic change in air fare across the dials, which is what supporters of this deregulation had predicted; what's missing, for the most part, are a lot of outmoded policies that resulted in much contorted programming by way of compliance.

Why else, foe example, did all-night deejays regularly interrupt their music and patter for back-to-back "public service announcements"? The answer had to do not with any sense of charitable or civic responsibility, but rather with requirements that stations devote certain amounts of time -- and never mind what time -- to public service. Similarly, until the Supreme Court decision, stations were not totally free to alter their formats from, say, classical to "news-talk."

These regulations, as well as limits on the number of commercials allowed in any given hour and intricate rules on log-keeping procedures, made sense when radio was young and the airwaves limited. But today, with some 9,000 stations on the air, the program offerings are diverse, and market competition works as a regulator. If a station is airing more commercials than its listeners can stand, they can tune away to another station; for that matter, many stations are now boasting about "commercial-free" hours of music. Even with all this new freedom, we have yet to hear any promotions for "music-free" hours of commercials. But more on that after these messages . . .