As PHP is 100% backend, it would be odd to expect it to work with web sockets on the front end. However PHP is perfectly capable of working with sockets so in that sense, you can indeed communicate with a socket. through PHP
PHP supports websockets. I am not sure where you read it but there is Ratchet ( WAMP1.0) which is abandoned because developer didn't have time to implement WAMP2.0 and Thruway which picked up the project and implemented one of the best php WebSockets.