Caller: Unknown

They have called me 4 times in the past three weeks. Never leave a message.

I had several calls from this number, I didn't answer. I found this information about the number:
"We are a social research company, exempt from the Australian Do Not Call Register, meaning we may call telephone numbers listed on the Do Not Call Register to conduct opinion polling and standard questionnaire-based research. We are not telemarketers, we are not selling a product and we do not provide your name or contact information to any other parties."

Had multiple missed calls No messages and when I did pick up there was a sniff noise then they hung up

Keeps calling, never leaves a message

rings only a couple of times has happened over several days

Survey from Monash Uni.
I was about to block them but they seem legit.

Haven’t picked up once but they keep calling me every few days

called me 4 times in the past few weeks

Have also called 4 times for the past 3 weeks. Never answer them but they never leave messages either.

i didnt answer but they keep leaving messages with no sound

They keep calling me, never leave a message and I couldn’t block them.