The 18-year-old singer wowed the Nine Network show's four coaches with her rendition of Edith Piaf's 'La Vie en Rose' and moved Delta Goodrem - who she eventually chose as her coach for the battle rounds - to tears.
> 'The Voice' Australia premiere cleans up in ratings
Leahcar told the Australian Daily Telegraph that although she impressed the panel on Australia's Got Talent, she was not put forward for the live shows.
She explained: "Even if all the judges say yes, you're not guaranteed you will go through... they all said yes, but I didn't get to go through."
Leahcar also revealed that she entered The X Factor when she was 15 years old, but failed to make it past the first round.
The teenager, who has a degenerative eye disease called retinitis pigmentosa and has lost 90% of her sight as a result, also said that she was moved when reading messages of support left for her on Twitter.
"There were a few people who messaged me saying I have or my daughter has this disability and I cried with every one (of those) I read," she added. "It's exactly what I was hoping for."
Watch Rachael Leahcar's audition on The Voice Australia below: