WASHINGTON — When it comes to deciding whether airline passengers can use their cell phones in flight, federal agencies are sending different signals to consumers.

The Transportation Department, which regulates aviation consumer issues, indicated in a notice posted online Friday it is considering retaining the 23-year-old ban on the calls, and asked for public comment.

Two months ago, the Federal Communications Commission voted to pursue allowing the calls. The FCC has responsibility for determining whether the use of cell phones in flight would interfere with cellular networks on the ground.

Polls show many passengers, particularly frequent fliers, oppose allowing in-flight calls from passengers’ cell phones. Echoing their concerns, the Transportation Department said it believes allowing passengers to make cell phone calls “may be harmful or injurious” to others.

“People tend to talk louder on cell phones than when they’re having face-to-face conversations,” the department said. “They are also likely to talk more and further increase the noise on a flight, as passengers would not be simply talking to the persons sitting next to them but can call whomever they like.”

Some planes already have seat-back phones, but they are rarely used, the department said, adding the concern “is not about individual calls, but rather the cumulative impact of allowing in-flight calls in close quarters.”

At the FCC, Chairman Tom Wheeler has said he wants to repeal the ban on cell phone use in flight, calling it restrictive and outdated. He also wants the airlines, not the government, to have final say.

In an Associated Press-GfK poll three months ago, 48 percent of those surveyed opposed letting cell phones be used for voice calls while planes are in flight, while 19 percent were in favor and 30 percent were neutral. Among those who’d flown four or more times in the previous year, the rate of opposition soared to 78 percent.

Delta Air Lines told the government last year that 64 percent of its passengers indicated the ability to make phone calls in flight would have a negative impact on their experience.

The FCC has already received more than 1,200 public comments on its proposal, almost all of them opposed to lifting the ban.

“Nobody, absolutely nobody, wants to be the involuntary audience of another passenger’s telephone conversation,” one commenter said.