The D.C. police department has installed a recording device to answer most of the calls to 911, the city's emergency number for reporting crimes, fires, life-threatening accidents and health problems.

Until Tuesday, calls to 911 had been answered directly by a dispatcher. Now callers get a recording with the following message: "You have reached the Metropolitan Police Department. Please hold on and your call will be answered in turn."

City Council Chairman David A. Clarke called the idea of a tape recording answering an emergency number "absolutely ridiculous."

"I had to call 911 when I was stabbed several years ago and I sure didn't want to hear a recording at that time," Clarke said through a spokesman.

Sgt. Joseph Gentile, a spokesman for the city's police department, said that the recording is an experiment and part of a program to update the antiquated system that has been plagued with problems.

"We are trying it out for a couple of weeks," Gentile said. "It is to let people know that the line will be picked up."

The 911 number logs more than a million calls a year, according to Gentile.

In several calls made to test the system this week, the message was repeated two or three times before a dispatcher came on the line.

Washington is the only jurisdiction in the area using a recording on its emergency number. Other area police departments answer the emergency calls directly. In Fairfax and Montgomery counties, the emergency telephone system even provides the dispatcher with an instantaneous visual display of the phone number and address from which a call is made. If the caller hangs up, the dispatcher immediately dials the number to check on the situation.

D.C. City Council member Betty Ann Kane (D-At Large) said that the council approved a new emergency phone system last year and called the tape recording "a step backwards."

"Our intention was to improve on the 911 system," she said. "It is a very expensive system which we approved. If this is what the taxpayers are getting, they are being ripped off."

The tape recording follows another unannounced change in the emergency system. In January, the D.C. Fire Department, which also gets its emergency calls through the 911 number, began to rank requests for ambulances by asking more questions of the caller. An ambulance is immediately dispatched in a life-threatening case but a less serious one may have to wait up to 20 minutes for service.

Police Officer Gary Hankins, an official with the Fraternal Order of Police, said that although the union has no authority over the emergency phone system, he has received several calls from persons complaining that when they called 911 the call went unanswered for 15 minutes.

"The tape is a device to at least let the caller know the system is working and the telephone call will be answered eventually," he said.

District residents have long complained about the slow response to calls made to 911. Gentile said, the new recording does not speed up the process of answering calls, but lets callers know they have reached the right number.

He said other changes in the system will be announced later in the summer.

The District emergency phone system, installed more than 14 years ago, has been plagued with problems including unanswered calls, long waits for dispatchers to answer and on at least two occasions, a complete loss of service.

The Metropolitan Washington Council of Governments conducted a study of areawide problems with the 911 number in 1984. The study concluded that more than 50 percent of the calls received on the 911 number by jurisdictions in the Washington area were nonemergency calls.

Gentile said that the nonemergency police number is 727-4326 and calls about festivals and other nonpolice business is 8-DC-HELP.