An audio switch is an IC (integrated switch) found  used in the switch configuration for 3-pole to 4-pole accessories typically found in equipment like mobile phones,mp3 devices and 3.5 to 2.5mm audio connection jacks

Audio switches also have a great feature called Moisture detection. Many devices now are portable and therefore face the issue of moisture being introduced to the device. This can then trick the device into thinking it has an accessory attached. This moisture detection in these switch ICs helps the device recognise false and improper attachments via moisture.

Audio type switches also have a range of other features such as;

• Operating temperatures range from -40°C to 85°C
• Send/End key pressed detection
• Automatic impedance detection in audio configurations