Sound of boiling as a disturbing noise and as a functional signal

Hot or even boiling water is often used in the household. During the process of heating the water, molecules become more and more active. Intensity of their movement depends on the temperature. Moving molecules are bumping into the container and causing audible noise. This audible noise can be regarded as a useful and functional signal on one hand, but some people find it as a disturbing noise. A MSX technology was developed. MSX technology is presented in this article, together with some results of applied active noise control. MSX technology uses a sound sensor for determination of temperature of the water and even more important, the state of boiling itself. Microphone is placed in the base of the kettle and is recording sound. A microcontroller regulates the power of kettle according to calculated algorithm, which is based on the sound signal. The boiling point of the water is the main regulation point and by monitoring the sound, we can detect it much better then by monitoring the thermal sensor, which is commonly used in digital kettles. A new step forward in MSX technology is integration of Active Noise Control algorithm. Such algorithm enables the use of generated noise for control purposes and it attenuates the very same signal with additional loudspeaker. Audible noise is attenuated and almost silent performance of the kettle is achieved.