“When the commission puts expediency ahead of an open process, it creates unnecessary resentment from parties that believe they were not given a fair hearing,” said Jonathan S. Adelstein, a commissioner. He said he nevertheless voted for the measure because he felt further delay was unlikely to change the outcome.

In addition to the broadcasters, the decision was opposed by the Broadway theater industry, which argued that new devices using the white spaces could interfere with transmissions from wireless microphones and among crew members.

A coalition of Broadway producers and performers joined the broadcasters in arguing that the F.C.C. should conduct more tests.

“We are deeply disappointed with the F.C.C. decision that could silence Broadway productions and those at other venues around the country,” said Charlotte St. Martin, executive director of the Broadway League, a trade group representing the New York theater industry.

The discussion over how to handle white spaces emerged in light of an impending change in the way television signals were delivered. Starting in February, TV stations will be required to switch to digital from analog delivery.

Since 2004, the F.C.C. has been studying whether the frequencies between television channels  the white spaces  could be used by other devices, particularly because digital signals are less prone to interference. The F.C.C. performed two sets of tests that showed some potential for disruption on frequencies used by broadcasters, live theater performances or others who rely on the same spectrum.

But F.C.C. commissioners said they had confidence that interference could be mitigated through tight regulation of new devices. For devices to be automatically certified by the commission, they must include technology that determines whether they are in a location where the channels are protected for use by incumbent broadcasters; if they are, they must find some other channel to transmit on.