Proud grandson David Whiting, sitting to Christina's right, says the family bought her the headphones and filled an MP3 player with Scottish tunes of yesteryear.
"We're on to our fourth pair now because she just wears them every day," the 35-year-old says.
"And we just turn it right up, because she is pretty deaf, and she just sits there and sometimes sings along."
There are a few things Christina still takes great joy from. Music is one of them. Food is another.
Today her family and friends will gather at Radius Matua for a special birthday lunch. There will be plenty of gifts.
David says his nana loves to eat, which she does really well for her age.
Her favourite is fish and chips but she is also partial to a savoury.
In fact, Christina had just finished a savoury shortly before the Bay of Plenty Times Weekend arrived to visit her yesterday.
David says she was always into baking and was very good at it.
"She can't do it anymore, she can't really see that well. But that was her big thing."
Some of his standout childhood memories are his nana taking him out for lunches during the school holidays. They would go to Farmers in town and often had sausage rolls.
"I can't believe it sometimes, when I look at her, that she's still here," David says.
"At my age anyway – at 35. I had my wedding at the start of the year, so to have her there was real cool. I never thought that would happen."
A few years ago David and his now-wife travelled over to Scotland and visited some of the places where Christina grew up.
She was born in 1915 in Dumbarton and later moved to Millport, a town on the Scottish island of Great Cumbrae.
Christina, who is from the McDonald clan, was a nurse for soldiers recovering from war wounds during World War II. She married in 1945 and had two children.
Christina and her daughter Jan Whiting immigrated to New Zealand in 1972 and Christina worked at Auckland Hospital for nine years before moving to Tauranga with Jan in 1981.
When the Bay of Plenty Times covered Christina's 100th birthday in 2015, she said the secret to living a long life was "Scottish blood and good food".
During that interview, she also spoke of being "joined at the hip" to her grandson David, who she had helped raise when Jan returned to work.
"She's like a second mum to me," David said in 2015.
Yesterday that close bond was still so clear.
During the Scotland trip a few years ago, David took photos for his nana – outside the post office she worked at in Millport, of her old houses and around her old town, and even at her favourite sunbathing spot.
With those photos, he created a book and the two of them often flip through its pages together.
That's something else that still gives Christina Barrie great joy.
Yesterday she had the photo book sitting on her lap as she listened to Amazing Grace and waved at the flashing camera with a smile on her face.
Who else was born in 1915?
•American actor, director, writer, and producer Orson Welles (Citizen Kane)
•Swedish actress Ingrid Bergman (Casablanca)
•Chilean dictator Augusto Pinochet
•American singer and actor Frank Sinatra
•American jazz singer Billie Holiday
