San Francisco saw a 34.6 percent reduction in gunfire between 2014 and 2015, the most of any city in California, according to a report by the shot-detection company used by the city.

The dramatic drop in gunfire was the fifth-largest of the more than 60 cities nationwide that use ShotSpotter, the technology that instantly notifies police of the whereabouts of gunfire and counts how many shots were heard.

The high-tech crime-fighting tool notified the San Francisco Police Department 1,071 times last year about possible shootings, said Officer Albie Esparza, a police spokesman.

“In San Francisco our focus has been on reducing gun violence and it appears that our efforts and community partnerships are having the desired effect,” Police Chief Greg Suhr said in a statement.

The department, which pays about $206,000 a year for the ShotSpotter system, did not immediately provide data on whether the reduction in gunfire was accompanied by fewer people getting shot. The homicide rate for San Francisco, the bulk of which involved gunshot victims, actually climbed from 45 in 2014 to 52 in 2015.

Esparza stressed that a reduction in gunfire means fewer chances for people to become shooting victims.

The city with the biggest drop in the nation in gunshots was Huntington Station, N.Y., which saw a 50.2 percent reduction. San Francisco ranked fifth in the nation behind Atlantic City, N.J., Brentwood, N.Y., and New Haven, Conn.

Other Bay Area cities that employ ShotSpotter, a private company based in Newark and backed by venture capital, reported decreases, too.

East Palo Alto went from getting 682 gunfire ShotSpotter calls in 2014 to 500 last year, about a 27 percent reduction. The Richmond Police Department reported a 5 percent decrease, and Oakland a 13 percent decline.

Capt. Ersie Joyner III of the Oakland Police Department said the city saw a double-digit decrease in nonfatal shootings. Homicides in Oakland, however, climbed from 80 in 2014 to 83 in 2015.

ShotSpotter CEO Ralph Clark said gunfire alone — whether or not the bullets pierce someone — should be counted in how people view gun violence.

“When you understand that kids are irreparably damaged from hearing constant gunfire around them, you can’t look away from that,” he said.

ShotSpotter detectors are placed throughout cities and, once the sounds have been vetted by a computer system, notify the police department how many rounds have been fired and where.

Most of the activations in San Francisco were around the Mission, Bayview and Northern districts, said Officer Grace Gatpandan, a police spokeswoman.

“In a sense, it’s a way for us to get ahead of people calling 911,” she said. “We get calls all the time of people reporting shots fired but we already know about it.”

ShotSpotter’s National Gunfire Index report, published Wednesday, found the bulk of gunfire incidents across the country to be in the late evening and early morning, with nearly half concentrated in the four-hour period between 9 p.m. and 1 a.m.

The report also found that Christmas was the most popular day nationwide in 2015 for people to fire their guns, excluding New Year’s Eve, New Year’s Day and the Fourth of July, holidays that usually see spikes due to celebratory shooting and not necessarily an uptick in crime. Firework booms picked up by the system were omitted from the analysis, company officials said.

Kimberly Veklerov is a San Francisco Chronicle staff writer. Email: kveklerov@sfchronicle.com Twitter: @kveklerov