iPod users are being warned by police to be vigilant on the roads after the death of a young woman who was hit by a car while listening to music.

It is believed to be the third case in the past year in which a pedestrian or cyclist listening to an iPod has been distracted and killed.

Life support for Taranaki woman Cushla Marie Girling was switched off on Sunday night after the 19-year-old was struck by a four-wheel-drive in New Plymouth.

She was walking home in the rain from work at a bakery, listening to music on her iPod, when she was hit.

Her mother, Carol Girling, told the Herald last night she bought the iPod for her music-loving daughter's 19th birthday in July.

Ms Girling said her daughter was usually very safety conscious, and she was struggling to understand what happened.

Police inquiries are focused on whether she was on a pedestrian crossing when she was hit.

Her body was found on the road 15m away from the crossing.

"I'm just reviewing in my mind ... I know how she walked home," said Ms Girling.

"She used to leave the bakery and walk across one street and go to the pedestrian crossing, so I find it hard to think she wasn't [on the crossing], but because of the distance involved she may not have been. I can't say yes or no.

"She had her iPod on, it was raining at the time and she had her umbrella down. The only one who will ever know [what happened] is Cushla."

Ms Girling said Cushla had 478 songs and several albums on the iPod - "She loved her music."

Sergeant Pat Duffy, of New Plymouth police, said Cushla's umbrella could have blocked her view, and her hearing could have been "obscured by her iPod".

People using iPods had to be extra vigilant because their hearing was compromised.

"Clearly more care needs to be taken," Mr Duffy said.

Witnesses were being sought and it was too early to know if charges could be laid against the driver of the Pajero SUV.

Cushla's mother is partially deaf, so she knows how important it is to hear properly, and agreed with the police message which she didn't believe was critical of her daughter.

"I think what they trying to do is get the message across that you don't hear anything when you're wearing it."

Cushla lived at home with her mother and twin brother Kieran. She had planned to study to be a primary school teacher and then hoped to travel.

"I'm just so proud of her. It is a tragedy, but I look at it that I've had 19 years, fabulous years, with this beautiful girl who was blossoming into a very beautiful young lady."

The family were told from the moment she arrived in hospital that she couldn't be saved and were with her when she died.

"The doctors didn't gloss over anything; they said there was no chance, she was brain dead.

"She was kept alive breathing ... to let her friends and family go and sit and talk with her."

Automobile Association spokesman Simon Lambourne said pedestrians had a role to play in road safety.

"Walking is one of the safest ways of getting around, but the bad news is pedestrians are extremely vulnerable."

He said motorists and pedestrians had a mutual obligation to each other, but it was crucial that pedestrians were aware of their surroundings and the traffic flow, and used proper crossings.

"Even a moment's distraction can create a very dangerous situation for pedestrians," he said.

It would be too much to ask people not to use iPods in the street, but if they were going to use them, they had to make sure the volume was at a level at which they could hear traffic coming towards them and were "aware of what's going on".

Mr Lambourne said the problem was acute in busy streets around Auckland, where people often stepped out onto the street without looking for traffic.

Auckland University audiology head Dr Grant Searchfield said putting MP3 player headphones into the ears altered not only the ability to hear but the ability to determine where the sounds were coming from.

"If you're fairly engrossed in the activity of listening to music or something you're enjoying, your attention tends to be focused on that and your ability to refocus attention on things of importance can be momentarily out of the picture ... really you're in another world."

April 2010: Kumiko Wakamiya Goodhall, 55, of Mount Maunganui killed after being hit by a goods train in Tauranga. Police believed her iPod may have prevented her hearing the warning bells and train engine.
November 2009: Gareth Hotham, 30, killed when struck by a train on Collins Lane in Te Puke. He was wearing an iPod. After the tragedy, the Rail and Maritime Transport Union tried to raise awareness that MP3 players and car stereos were distractions that could lead to tragedy.