Today some cheapo eBay adapters arrived which were advertised as headset splitters, ie one socket for mic and one socket for earphones. These were not them. They were simply two way splitters. They were cheap enough not to complain about so I hacked the plug off and got to work. PS4 controllers use the CTIA standard of plug. So the tip is left, the first ring is right, the second ring is ground and the sleeve is mic. There are some other images if you click the thumbnail to see the gallery.