It is an instant recorded message that begins as soon as the line pick up. Since my line goes to voice mail (with a response), I am missing the introduction.
Their message asks me to phone with "code ..." followed with a 4-digit number.
Area code 322 is in Mexico.
It is often linked to scam calls (as most people will not check).

It is an old scam (almost as old as the Nigerian millionnaire widow): you call back the number and either you have unknowingly dialed a toll number (large fee on your next phone bill) or they get your bank information by simply asking you.
 Apr 20th, 2015