The tones are of at least two types, are more frequent than usual, are loud enough to be heard beyond the campus and are disrupting the normal daytime peace of nearby neighborhoods, resident Danna Breen told the council.
The Portola Valley School District essentially concurs and is taking steps, district Superintendent Tim Hanretty told the Almanac.
The council listened to Ms. Breen but did not comment. Under the rules for parliamentary procedure, comments would have been inappropriate since the matter was not on the formal agenda for the evening.
"Everybody is really shaken about this. It's like the Sound of Music. Every class has a sound to which they jump," she said. "I'm telling you it's wildly intrusive."
"Every 15 minutes the bell is ringing twice," she added. "I am speaking on behalf of a lot of people. We will drag the troops in (to a council meeting) if it doesn't stop soon."
"Bell is not the right word," Jon Silver, a resident and a former mayor, added. "It's more like an ersatz train whistle. It is odd. It is frequent."
"We think it very raucous and needlessly loud," Hartha Hanerfeld, a neighbor of Ms. Breen's, said in a telephone interview. The bells are audible on remote hikes on Coal Mine Ridge and Windy Hill, she said.
"It sounds like a siren," said Tan Oak Drive resident Mary desJardins in a phone interview. "It's auditorially disruptive. I can hear it all day long. What they have right now is like bad noise pollution. It's a very unpleasant sound."
Robert Pierce, also of Tan Oak Drive, called the bell "an annoying horn or klaxon."
Mr. Silver had recommended, since public school districts are not constrained by zoning laws, that the council try gentle diplomacy but it appears that may not be necessary.
Mr. Hanretty acknowledged the problem in forwarding to the Almanac a recent email message to Town Manager Angie Howard.
The school is perched alone on a hill in a relatively densely populated area of Portola Valley. The school bells were reprogrammed this year to accommodate a new three-part class schedule for fourth- and fifth-graders, for sixth-graders, and for seventh- and eighth-graders, Mr. Hanretty wrote.
"I concur that the tone that was added to accommodate the third (new) bell schedule is quite shrill," he wrote. "We are working to replace it with something less shrill."
Another problem: the speakers outside the classrooms are supposed to be heard just four times a day: when classes start, at the ends of recess and lunch, and at the end of the day. "At present, it appears that the bells are ringing inside and outside throughout the day," Mr. Hanretty wrote.
"Like so many things these days, we are not able to program the bell system ourselves," Mr. Hanretty continued. "We rely, as so do most schools in this area, on an outside firm to handle changes and adjustments to the system."
The Bay Area has just one firm that services this type of bell system and Portola Valley is in the queue, Mr. Hanretty wrote. The administration is also looking into reducing by half the duration of the ringing.