In the voice reminder function, the microphone sensor is used to detect the user's voice commands. When the user issues a voice command, the microphone sensor captures the sound signal and converts it into an electrical signal. Then, signal processing algorithms will analyze these electrical signals and extract the feature information in the sound. Finally, this feature information is used to trigger appropriate actions, such as playing voice reminders, adjusting settings, and so on.
It is important to note that the voice reminder feature may also require the support of other sensors and hardware, such as accelerometers, gyroscopes, light sensors, and so on, in order to achieve richer functionality and a better user experience.