PLEASANTON -- An investigation into the September beating of a 51-year-old Pleasanton man is on hold until the father of two, whose health is steadily improving, can communicate what he remembers of the night he was knocked unconscious while asking teens to keep their noise down, officials said.

Authorities say David Lamont, founder of Pleasanton-based marketing agency Marketsage, has awoken from the medically induced coma he was placed in after he received a major head injury Sept. 20 outside his home on Middleton Place. He was recently transferred out of the intensive care unit and into another hospital.

While he is conscious and his health is improving, he remains on a ventilator and feeding tube and has not been able to speak a word to investigators, Pleasanton police Sgt. Kurt Schlehuber said.

"The threat of him dying has passed. He has made it through the critical stages, and he's on his way to recovery," Schlehuber said. "But we haven't been able to talk to him, and I don't think anyone has. He's taking very small steps, and we're still hopeful he may remember something."

Lamont was home with his wife and two teenage daughters the evening of Sept. 20 when he heard loud voices coming from a field at the end of Middleton Place, a cul-de-sac of million-dollar homes southeast of Bernal Avenue. Teens often gather on the grassy hillside, part of Bonde Ranch Open Space, and Lamont reportedly went outside just before midnight to confront a group of noisy adolescents.

When Lamont did not immediately come back inside, his wife went outside and found him lying in the street, breathing but unresponsive. He was taken to Eden Medical Center in Castro Valley, where he remained in critical condition for close to a month.

While police have interviewed four teenagers as persons of interest -- all were at the scene Sept. 20 -- no arrests have been made. Schlehuber said the lack of charges does not necessarily mean the teens have been cleared.

"Once arrests have been made, there starts a clock," Schlehuber said. "We have to present a case very quickly, and without being able to talk to Mr. Lamont, we don't have a full case yet. There's a lot of stuff going on and no independent witnesses, so we're waiting for the opportunity for the victim to tell his side of the story."

Pleasanton police investigators have discussed the case with the Alameda County District Attorney's Office and are prepared to move forward with the case once Lamont is able to round out the investigation with his recollection, Schlehuber said. Anyone with information about the case is asked to call Pleasanton police at 925-931-5100.

Follow Erin Ivie at Twitter.com/erin_ivie.