Their work is likely to be associated with biometric functions.
According to a well-known resource DigiTimes, light sensors may appear in Apple AirPods wireless headphones, the release of which will be undertaken by Taiwanese company ASE technology.
The latter allegedly even began to purchase special equipment for this. It is expected that such sensors can appear in AirPods within a year or two.
But what the purpose of these sensors will be is incomprehensible. In smartphones, they adjust the brightness of the screen depending on the lighting in the room or on the street, but there is no screen in the earphone. Most likely, these sensors will be tied to the work of biometric functions – such as monitoring heart rate and determining blood oxygen saturation. But how this will be implemented is still a question.