So when she accidently leaves her phone at home, she starts to feel anxious.

"A lot of the reason I'm engaged with my smartphone is for work," the 23-year-old said. "People expect you to be contactable ... that you are always your professional self, and you are available".

Ms Groth is one of 7.3 million Australian smartphone owners who agree with the statement "I can't live without my mobile phone", up 55 per cent in the past five years, according to research firm Roy Morgan.

This number has increased with the rise in smartphone ownership.

"Even the earliest smartphone adopters were quick to forget how they ever survived without one," said Michele Levine, chief executive of Roy Morgan Research.

"The proportion of owners agreeing they 'can't live without it' has been fairly steady at just under half for the past five years —  a rate about three times higher than among 'dumb phone' owners asked the same question."

Jenny Kennedy, communications scholar at the University of Melbourne, says we now live in a culture of connectivity.

She says people are too often scared about what may happen if they don't have their phones.

"We feel that we have to constantly be connected. So that means constantly checking out emails, constantly checking our social media accounts in order to show we are present," Dr Kennedy said.

However, she also admitted she couldn't live without her phone.

"I put my hand up, I'm equally guilty of saying I'll just check social media one more time and I'll press the refresh button and it's telling me it was updated just two minutes ago," she said.

The Roy Morgan research also showed the biggest reason why smartphone owners needed the device was to help them juggle work and personal life, followed by personal security.

Ms Groth said without her phone she would struggle to be on top of all her work and social commitments.

"With my old job I was required to reply to emails straight away even when I wasn't working," she said.

"I am lucky to have a workplace now that sets boundaries but many do not."

Ms Groth said she has relied on her Apple iPhone for safety in many situations.

"I was walking home through Redfern the other night and I felt unsafe so I called my friend," she said.  "It is amazing to be able to be seen to have contact with someone for personal safety."

The research also showed Apple iPhone owners were the most loyal, with 50 per cent saying they couldn't live without their device.

In sharp contrast, only one-third of Nokia, Huawei and Sony smartphone owners felt the same way about their device.

"[Huawei phone owners] are less likely to use many of the different smartphone services we monitor including taking photos, playing music and games, streaming videos, using GPS and Bluetooth functions, and downloading and using different apps," said Ms Levine.