This is a possible phishing or other information gathering service. The reason why you don't hear an answer or voice is, this is electronically set up by a service to verify that someone is at that phone number. It doesn't care who, just that someone answered. Unfortunately, this also goes for voicemail. This software captures the fact that someone or their voicemail answered & then stores the address & other info associated to the #. Then it puts it on a list. That list is for sale by info collection & list building services. Then companies buy these lists so they can solicit you for their products/service. You can try getting your info unlisted, but you may have to pay to get this done.

Calls each day leaves no message and does not take return calls....pretty much same as KJ

calls with no answer, leaves voicemails with sounds in the background, calls repeatedly once 11 times in less than and hour