Smart optical microphone/sensor

A smart optical microphone/sensor comprising:

• a membrane mounted for flexible movement for receiving and undergoing motion responsive to sound, the membrane having a light-reflecting surface;
• means for sensing motion of the membrane responsive to sound including,
• a source of light fixed with respect to the membrane for illuminating the light-reflecting surface of the membrane, the source of light having a power input and outputting light proportional to power at the power input;
• adjustable means for supplying adjustable power to the power input of the source of light;
• a photodetector having a light input fixed with respect to the membrane and an output responsive to the light received at the photodetector input, the photodetector for receiving light from the light source reflected from the light reflective surface of the membrane at the input, the photodetector producing output signals which are a combination of the power to the power input of the source of light and the movement of the light reflective surface of the membrane;
• and,
• a pre-amplifier connected to the photodetector output for amplifying the output signals,
• whereby the sensitivity of said microphone/sensor can be adjusted by the adjustable means for supplying power to the light source.