Updated: Aug 24 2018
The curved transparent panel that all MartinLogan ESL speakers use is called an electrostatic transducer. The transducer converts energy from one state into another. The electrical energy from your amplifier is converted into mechanical energy via the motion of the ESL's diaphragm. This causes the air pressure in your listening room to rise and fall exactly as the recorded music does. The sequence of rising and falling air pressure is picked up by your auditory system and interpreted by your brain as sound.