I'm using an HP EliteBook 9470m. It has one single combined input jack for microphone and headphone. I get clear nice sound with headphones missing a microphone, i.e headphones with only a three contact jack as shown on the right in the picture below.
When I use my phones headset (four contact connector on the left in the picture below), I get somewhat weak sound. I have to keep pressing the headset's button to get full sound quality.
I assume Ubuntu does not auto-detect the kind of jack that is plugged in. How do I get Ubuntu to recognize my mobile's headset?