I got a call from (613) 688-5051 and when we answered we heard children laughing in the background.

Health Canada doing research on eating out. They left a message on my machine telling me to call back and gave me a case number. Called again today since I didn't return call yesterday. No time fr surveys. I'm blocking them.

Callers from this number do not leave messages, hang up when phone answered, can not be reached by calling 1 (613) 688-5051.
When phoning back to this number:
Calling direct, the message is "this number is out of service.:
The number can not be reached by dialing 0-(613) 688-5051. Operator indicates the number could be a call center or other marketing service which is only equiped for outbound calls.
Also telephone booth service phones can not be reached by calling them back.

Not a scam. Not sure why the call didn't go through. You can also try (613) 688-5051 or toll free +1 877-688-5051

A man called from (613) 688-6051 and said he was from Health Canada doing a survey on chronic diseases.

Thats a bit much to set up.