Sitting alone in the empty stands at the Tokyo Olympics, Mackenzie Arnold was acutely aware of two things.

The first: her World Cup dream was quickly slipping from her grasp.

The second: she needed to get her hearing tested.

Less than two years on, Arnold has pulled off a meteoric rise from the Matildas' fringe to Tony Gustavsson's first-choice goalkeeper ahead of a Women's World Cup on home soil.

She's also just been fitted for her first pair of hearing aids.

"It's been a bit of a whirlwind," Arnold told AAP.

"To be honest, obviously the last two World Cups I haven't been able to get any game time.

"So potentially coming to this one as number one 'keeper is a lot to take in but something that I'm really excited for, especially being at home."

Arnold always starred at club level, at Brisbane Roar then more recently, for English Women's Super League club West Ham.

But taking that form into international level has always been difficult for the 29-year-old, who has just 34 caps since her Matildas debut in November 2012.

Compared to close friends Alanna Kennedy and Caitlin Foord, an inconsistent Arnold was never able to hold down a spot, with Lydia Williams and Teagan Micah preferred for Tokyo.

"After being left out of the Olympic squad, and being in the stand for that (as an alternate player), I had a feeling that I didn't really want to feel again," said Arnold.

"I wanted to be a part of the success of the team.

"It was more of a mindset thing. It was almost like a now or never kind of thing and I knew the World Cup was coming up and it was almost like I was running out of time to get that position for myself."

So Arnold got to work at West Ham, underlining her status as one of the WSL's best custodians.

"It's one of the best leagues in the world and playing up against those girls as well, it really puts you up against elite athletes," she said.

"It just takes you out into a different environment, more of a professional environment and gets you to be a part of a bigger world.

"Once I got comfortable with that, and I knew I could do that, I just needed the chance with the international team and thankfully I've taken it and hopefully I can keep going into the World Cup."

That chance came in February's Cup of Nations, when Arnold was given first dibs in goal ahead of Williams and Teagan Micah, who starred in the Olympics.

She was the player of the series, then against England earlier this month, looked more assured than ever.

"It's probably the most comfortable I've felt to be honest," she said.

"After the Cup of Nations and having that success as a team and getting that consistent game time, it was three games in a row.

"It really put me in a different mindset that I almost belong there now, instead of trying to prove a point."

Comfortable on the field, this year Arnold decided to act on something that had been holding her back off it since her early 20s.

"The girls have always said 'you need to get your hearing checked' and it was something that I knew, but I don't think I wanted to accept the fact that my hearing might be a lot worse than I thought," she said.

"But then when COVID hit and everyone was wearing a mask, I really struggled because I obviously found that I was probably lip-reading a lot before that time.

"So when the masks came into play and I was really struggling, I thought 'probably now's the time to get my hearing checked' - and it still took a year or a year and a half to do that."

When it was confirmed Arnold would need hearing aids, she knew who to turn to.

Brother Sam was diagnosed with hearing loss as a five-year-old and has worn hearing aids since.

"He really helped me in that process to accept it and just be like, 'well it is what it is and it's going to improve your life so much' and I think that really helped me into taking that next step," she said.

The first thing Arnold noticed was what she thought was white noise. It was a computer starting up.

"My partner was with me at the time and asked me before I put them in if I could hear the rain, and I couldn't and as soon as I put them in, I could hear it," she said.

"The only way I can explain it now is if I take them off, it feels like someone's got their hands on my ears."

Arnold is yet to wear her hearing aids in a game or at training, preferring to gradually adjust before introducing that to her on-field life.

But her decision is already making an impact.

Arnold posted a video to Instagram of her journey towards collecting her hearing aids.

It brought an outpouring of support from current and former teammates, along with plenty from those she'd never met.

"There's been actually quite a few messages from parents and kids who've been playing with hearing aids and some people that are my age as well that have thanked me for speaking out about it," she said.

"So that's been cool to see and reassuring that it was the right decision to put it out.

"To get that kind of response and to actually help others along the way - it's actually been really rewarding."