We get calls from this number a couple times a week every couple months. If we answer there is nobody on the line. When I called back, the answering machine says they are a Independent Survey Organization.
We get a call a couple times a day for a while then nothing. When I answered the phone guy was talking in a regular tone then changed his accent and said he was from my local health department.
I also have been getting these annoying phone calls. Just a few minutes ago, got one. So I picked up and the female wanted to know if I wanted to take a survey. I said no and hung up.