The kitchen timer ticks down the minutes in Lorraine and Robert Zuber's tidy Lower Towamensing Township home, setting off both the ringer and a small, black four-legged bundle of exuberance named Colby.

Springing from a brief nap on the living room floor, Colby races from the timer on the stove to Lorraine, touches his front paws to her knee and dashes back to the timer.

Zuber smiles as she praises Colby and feeds him a treat. "Good boy!" she tells him.

The reward reinforces the mixed-breed dog's performance in alerting Zuber to the ringing of the timer, a sound she cannot hear.

Colby is a hearing service dog that is being trained to alert Zuber to everyday sounds that hearing people take for granted: a knock at the door, the ring of a telephone, the blare of a smoke alarm, the buzz of an alarm clock or kitchen timer and the sound of Zuber's name being called.

Zuber, who lost her hearing as a young adult, applied for a hearing service dog in 2006 from Dogs for the Deaf, a Central Point, Oregon, organization that finds, trains and places hearing service dogs.

Today, Colby's trainers, team leader Jodi Hangartner and apprentice Kaye Geyler of Dogs for the Deaf, are finishing a five-day program that makes sure Colby and Zuber are a good match and that Colby is transferring his allegiance from Geyler to Zuber.

"That's why we do the placement in the recipient's home. Everybody's phone sounds different," Geyler said. "The houses are all set up differently. Coming with the dog, we are able to help the dog adjust to the new environment."

For Zuber, having Colby means being able to live a more ordinary life; for Colby, it means life itself.

Colby, as are other Dogs for the Deaf, was found in a shelter.

"They are mutts from pounds," Hangartner said.

But they are very special mutts. Hearing service dogs must meet certain criteria.

"We want the ones that are standing in the front of the kennel, the ones that are making eye contact, the ones whose body language is very friendly and open," Geyler said "We are looking for confident, happy dogs that are energetic and looking for something to do."

Colby, whom Geyler describes as a "scruff-muffin terrier," was found in a Washington state shelter by Heather Wise, who works with Paws Across the Northwest, a group that raises awareness of the need for homes for animals and aims at increasing communication among rescue groups, shelters and private parties.

"She found him and brought him to us in May," Geyler said.

Typically, Dogs for the Deaf canines are found by the organization's own trainers, Hangartner said.

Colby is, at best guess, about 18 months old. He seems to have only two speeds: high energy or lying flat-out on the carpet, his favorite toy within easy reach.

Zuber is delighted with her new friend.

Her hearing loss was gradual, and probably caused by a viral infection she caught while in junior high school. Sounds began to disappear from her life while Zuber was in her early 20s.

"I couldn't hear my watch tick any more," she recalls.

But the slow loss was a blessing of sorts, allowing her to adjust. She's used hearing aids since age 25, and recently had a cochlear implant, but the device has yet to function fully. The implantation procedure left her totally deaf in her right ear, so at night, when she takes out the hearing aid she wears in her left ear, "I'm almost totally deaf," she said.

She's familiar with hearing service dogs, having had one for a time in the 1980s. "That was a godsend," she said.

But that dog became blind. She got another, but that one didn't work out because he didn't like children.

In 2006, the couple traveled to Oregon to visit Dogs for the Deaf.

"I was very impressed with the facility," Zuber said. "I applied for a dog then – it was a little longer wait than I expected."

There's a good reason for that, Geyler said.

Dogs for the Deaf has been in business for 30 years," Geyler said. Because of that, it has an extensive "list of recipients whose dogs have passed. Because they are used to having a dog and are actually at a loss with losing their dog, we put them at the top of the list."

The organization is scrupulous about matching dogs to recipients; both are extensively evaluated for personality, lifestyle and other factors.

Dogs for the Deaf, a nonprofit organization accredited by Assistance Dogs International, was "founded in 1977 by the late Roy G. Kabat, a longtime Hollywood and circus animal trainer who raised animals for motion pictures and television shows including "Dr. Doolittle" and "Born Free." His daughter, Robin Dickson, is his successor and the CEO/president of Dogs for the Deaf," the group's Web site says.

Dogs whose recipients cannot keep them or who have passed on return to Dogs for Deaf.

Dogs for the Deaf places the canines in recipients' homes free of charge. The group depends upon donors to offset costs.

Colby, who will wear a bright orange hearing service dog jacket and matching collar, has public access rights. That means he is allowed into restaurants, stores, libraries and other public places, Hangartner said.

"He can be in the company of Lorraine everywhere she goes," she said.