SOUND TRANSDUCER – 21124
A sound transducer, also called an acoustic transducer, is an electronic component that converts acoustic waves into some other form of energy, or vice versa. The other form of energy is usually an alternating-current (AC) electrical signal. The waveforms of the acoustical and electrical signals are identical, or nearly so.
Acoustic transducers are designed for various frequency ranges. The human hearing spectrum extends from about 20 Hz to 20 kHz, but acoustic energy can have frequencies lower than 20 Hz or higher than 20 kHz. Energy at frequencies below 20 Hz is called infrasound; if the frequency is above 20 kHz, it is ultrasound. In acoustic wireless devices, ultrasound is generally used, because the wavelength is short and the necessary transducers can be small. Also, ultrasound cannot be heard, and therefore it does not distract or annoy people.
Sound transducers are used in security systems. They are also used in robotics to help mobile machines navigate in their surroundings. Acoustic transducers are employed in depth-finding apparatus commonly found on boats.