Ps3 Bluetooth headset and Siri

Hi, I'm using a Ps3 headset (the older one) and I'm trying to use siri. However, siri won't stop listening when I stop talking. The only way to stop this is to mute the device but that means I can't send messages or anything. I tried pressing the power button like I do to activate siri, but that just shuts down siri. If anyone can help me with any other ways to use siri with it that would be very helpful. Thanks