In Dutch, Lourens is pronounced exactly the same as Laurens: LOW-rəns.Also compare other Dutch given names that contain -ou-, such as Boudewijn and Wouter. [noted -ed]
Lourens is used as a masculine name in West Frisia (located in The Netherlands), but also here and there in The Netherlands itself (either by non-Frisian parents that simply have a love for Frisian names, or by parents that wanted an alternative spelling for the more common and plain Dutch name Laurens).
Also compare other Dutch given names that contain -ou-, such as Boudewijn and Wouter. [noted -ed]