The 30-year-old noise code that dictates everything from how loud jackhammers can drill and to when ice cream trucks can play jingles is coming under review today at the City Council.

The council’s committee on Environmental Protection will begin hearing testimony this morning from representatives of Mister Softee, the ice cream vendor, and from other groups affected by noise regulations, on a bill proposed by Mayor Bloomberg designed to turn down the city’s volume.

If passed, the bill would, among other things, implement more stringent noise requirements at construction sites, reduce allowable music volumes at clubs, lower the threshold for ticketing residents with barking dogs and loud lawnmowers, and increase noise fines across the board.

Council Member James Gennaro, chairman of the committee that introduced the bill at the mayor’s request, said while the Bloomberg administration had a strong show of support for the proposal when it was rolled out in June, now it appears that the endorsements have, well, quieted.

“They seemed warm and friendly to it back in June. Now I’m hearing other things,” Mr. Gennaro said yesterday, referring to the New York Nightlife Association and other industry groups. “What we want to do is to determine whether that warmth has carried over into the New Year.”

Mr. Gennaro reserved judgment on the full bill, but said “it made no sense” for the administration to exclude what he characterized as the city’s primary noise problem: Car alarms.

In September, the council overrode a mayoral veto and banned the installation of car alarms that either sound for longer than three minutes or are motion-activated. The mayor had argued that alarms were addressed in the existing city noise code and said the ban would drive car owners outside the city to get alarms installed.

The vice president of Mister Softee, the ice cream vendor whose jingle was targeted as a chief annoyance by Mr. Bloomberg’s last year, said yesterday that he was confident about coming to a compromise.

Mr. Bloomberg’s proposal includes completely banning the Mister Softee jingle starting in 2006. The executive, James Conway Jr., who is scheduled to testify to the council today, said that was not fair, but the company would agree to stop the music when trucks were parked to eliminate the incessant jingling that pedestrians find irritating.

“The code as it is written would obviously have an extraordinarily negative impact on our business,” Mr. Conway told The New York Sun.

The company’s franchises, he said, contribute substantially to the local economy. They have 350 ice trucks in the five boroughs, an estimated 500 employees, and they purchase their ice cream from a city vendor.

The legislative consultant for the Queens & Bronx Building Association, Robert Altman, said yesterday that the code, as written, does not provide developers with enough information about what they need to do to comply.

Mr. Altman, who will also testify today, said the association would support “common sense” changes, but stressed that new regulations make it harder for developers to operate in the city.

“This is a city of 8 million people, this is not the Catskills,” he said. “We are going to make noise.”

“This is the most expensive city in the country to do construction in,” he added. “Does the administration really want to add to that cost? Everybody in this city is talking about affordable housing, but you’re talking about another regulation here. Who’s going to pay for it?”

The proposed code would have a widespread affect on all city residents. Those with lawns in Queens and on Staten Island, for one, would not be able to mow them before 8 a.m. or after 7 p.m.