This appears to be Survey Sampling International, you can check them out at surveysampling.com If you do not wish to speak with these people and you have the ability to block numbers, then you will want to block the following:
From their website: SSI (www.surveysampling.com) is the premier global provider of sampling, data collection and data analytic solutions for survey research, reaching respondents in 78 countries via Internet, telephone, mobile/wireless and mixed-access offerings. Additionally, SSI staff operates from 26 offices in 18 countries, to offer CATI, questionnaire design consultation, programming and hosting, online custom reporting and data processing. SSI serves more than 3,000 clients worldwide.
I use PhoneTrayFree software on an older computer with a modem, and have added all the numbers above to the block list using the "?" wildcard. PhoneTray has incredible flexibilty to customize blocking, and allows unlimited entries. Unfortunately the free version is no longer offered, but there is a 15-day free trial for a pro version ($30 to buy, or $60 with a USB modem).
I've been using this program for over a year with a cable company landline, and I HIGHLY RECOMMEND it. It's great for taking control over unwanted calls of any type. The only minor downside I've found is the phone will ring at least once (customizable # of rings) before the call is blocked, which allows the Caller ID info to come through.
Go to www.phonetray.com for details.
(And, no, I am not affiliated with this site - I'm just a very satisfied customer.)