Abstract: An electrodynamic transducer having a coil, a membrane, and a plate is disclosed, wherein the transducer is adapted to generate a sound pressure level in the human-audible acoustic range and the ultrasonic range so that the transducer may be used as a speaker and an ultrasonic proximity sensor. The transducer may be adapted to generate a sound pressure level above about 88 dB between 20 kHz and 70 kHz. The plate may include a structural rigidity increasing feature such as a domed portion or a population of ribs, which may increase the generated sound pressure level in the ultrasonic range. The transducer may also include a front resonator which may be used to further tune and/or increase the generated sound pressure level in the ultrasonic range.

Abstract: The disclosed active noise suppression headphone system is directed to a headphone system that is capable of substantially suppressing high or low frequency interfering noise that penetrate through a headphone earpiece from multiple directions. An external microphone mounted with a housing of a headphone earpiece senses ambient noise outside of the earpiece. The sensed ambient noise may be processed through at least one parallel filter bank arranged in at least one headphone earpiece. Each parallel filter bank may include adaptively linked filters. The output of these filters may be amplified based on weighting factors that are dependent upon the sensed ambient noise and that are generated by a filtered x least mean square circuit. The amplified filtered outputs may be summed to generate an antinoise signal that is in input to a loudspeaker within the headphone earpiece that substantial suppresses the ambient noise before it can be perceived by an end user of the headphones.

Abstract: The disclosed active noise suppression headphone system is directed to a headphone system that is capable of substantially suppressing high or low frequency interfering noise that penetrate through a headphone earpiece from multiple directions. An external microphone mounted with a housing of a headphone earpiece senses ambient noise outside of the earpiece. The sensed ambient noise may be processed through at least one parallel filter bank arranged in at least one headphone earpiece. Each parallel filter bank may include adaptively linked filters. The output of these filters may be amplified based on weighting factors that are dependent upon the sensed ambient noise and that are generated by a filtered x least mean square circuit. The amplified filtered outputs may be summed to generate an antinoise signal that is in input to a loudspeaker within the headphone earpiece that substantial suppresses the ambient noise before it can be perceived by an end user of the headphones.