FINRA Rule 3170 requires firms to establish, enforce, and maintain written procedures supervising telemarketing activities of all its registered persons, including recordings of the conversations.
Link to Rule: http://finra.complinet.com/en/display/display_main.html?rbid=2403&element_id=11348
Helpful Link: http://finra.complinet.com/en/display/display.html?rbid=2403&element_id=11470