Bertie has revolutionised his owner's life

Several short bounds take him across the bedroom, and within moments of the signal, he has landed beside Gill Stevenson.

He knows that it is his responsibility to wake her up.

Such a sudden arrival would be more of an inconvenience if Bertie were not a miniature Yorkshire Terrier.

He is, perhaps, 12 inches long and, certainly, not very heavy. But luckily for Gill, his diminutive stature is at odds with the diligence and intelligence he brings to his job.

Gill is profoundly deafened, and Bertie has been trained by Hearing Dogs for Deaf People to act as her ears.

While the organisation has placed 800 such dogs across the UK, Bertie is one of only two Wales.

Bertie has been taught to react to specific sounds, and alerts Gill with his paw when the telephone rings, or there is a caller at the door or if there is an unusual noise. He then leads her to the source of the sound.

But the dog has developed other instincts, and recently has been the focus of media attention unprecedented of a terrier.

It is not unusual for our dogs to display an instinct for helping and protecting people, but Bertie's actions were very special

Jill Moir of Hearing Dogs for Deaf People

Bertie has entertained three camera crews since being named the Hearing Dogs for Deaf People's Dog of the Month for November.

He earned this accolade for his actions while Gill was in hospital surgery in Cardiff's University Hospital of Wales.

Dozing on her bed, he woke suddenly and became very agitated.

"He stood bolt upright and started barking at the lady in the opposite bed," said Gill.

"We couldn't quieten him down, we didn't know what was wrong.

"One of the nurses went across to check that she was all right and in fact she wasn't all right."

Hospital staff were astounded to discover the patient to which Bertie had alerted them had stopped breathing.

They rushed equipment to the scene, and she was resuscitated.

Bertie in his working jacket

It was agreed that Bertie had helped save her life. But his instinct for helping people does not end there.

At home one afternoon, Bertie kept alerting Gill with his paw, and leading her to the hall door. Each time there was no one there.

Gill was confused, but, again, Bertie refused to be ignored.

Finally she opened the door, and followed Bertie outside. There she discovered a girl who had fallen and hurt herself.

Bertie had heard her crying, and wanted to let Gill know that someone needed help.

Jill Moir, spokesperson for the charity, said "It is not unusual for our dogs to display an instinct for helping and protecting people, but Bertie's actions were very special."

But when the dust has settled on this story of heroics, Bertie will still be carrying on with what is his most remarkable work. That is his improvement to the quality of Gill Stevenson's life.

"I simply could not live without him", says Gill, who started to lose her hearing in November 1996, and is now profoundly deaf. She lived without an assistance dog until receiving Bertie from Hearing Dogs For Deaf People in January 2000.

Bertie did so much to remedy my feelings of isolation and depression that often come with deafness

Bertie's owner Gill Stevenson

"They opened the door, and he bounded in, and that was that," recalls Gill of her first meeting with Bertie.

One of the most immediate benefits Gill felt on his arrival at her home was his making her feel less isolated.

"With Bertie, I started to receive visitors again," explained Gill.

"Before, I had always been in, but I couldn't hear the doorbell, and missed out on visitors calling round. I can't tell you how unmotivated my life had become.

"Bertie's arrival was a complete revelation. He did so much to remedy my feelings of isolation and depression that often come with deafness."

Praise indeed. But despite Meanwhile, his head remains as miniature as ever.