In general, the subject matter described in this disclosure can be embodied in methods, systems, and computer-readable devices. An audio processing device plays a source audio signal, including causing the source audio signal to be audibly output by an electroacoustic transducer of a user earpiece. The audio processing device records, while playing the source audio signal, a recorded audio signal using the electroacoustic transducer. The audio processing device identifies one or more parameters that indicate how properties of the user earpiece affect playing of the source audio signal, at least one of the parameters being temperature dependent. The audio processing device determines a temperature value estimated to cause the source audio signal that was played by the audio processing device to result in the recorded audio signal, accounting for changes to the source audio signal that occur due to the one or more parameters.

Ultrasonic transducers that are capable of generating increased levels of ultrasound, as well as receiving ultrasonic waves with increased sensitivity. The ultrasonic transducers include a back cover, a protective front cover, a backplate, and a vibrator film layer disposed between the backplate and the protective front cover. The backplate includes a plurality of grooves formed on a surface thereof facing the vibrator film layer. Each groove includes upper edges having cross-sectional contours that gradually tend toward the deepest part of the groove to allow a larger area of the backplate to be closer to the vibrator film layer, thereby increasing the resulting electric field, and, consequently, increasing the output power and sensitivity of the ultrasonic transducer.

An ultrasonic generator includes a substrate, a lower electrode on the substrate, an upper electrode on the lower electrode, and an ultrasonic generation unit between the lower electrode and the upper electrode. The ultrasonic generation unit includes a vibration chamber and an ultrasonic generation layer on the vibration chamber. The ultrasonic generation layer is configured to propel a surrounding medium to vibrate to generate ultrasonic waves in response to a voltage difference between the upper electrode and the lower electrode.

Systems and methods for loudspeaker layout mapping in accordance with embodiments of the invention are illustrated. In many embodiments, loudspeakers are able to generate tones which are used by other loudspeakers to generate impulse responses. The impulse responses and the angles at which the tones were received can be used to determine the relative locations and orientations of the loudspeakers. In various embodiments, obstacles which obstruct the path of the tone can be identified and accounted for.

A system, including a first microphone of a non-body carried device and a processor configured to receive input based on sound captured by the first microphone and analyze the received input to determine whether the sound captured by the first microphone is indicative of an attempted communication between humans, which humans are located in a structure where the microphone is located, upon a determination that the sound is indicative of an attempted communication between humans, evaluate the success of that communication.

Systems and methods for suppressing noise and detecting voice input in a multi-channel audio signal captured by a plurality of microphones include (i) capturing a first audio signal via a first microphone and a second audio signal via a second microphone, wherein the first and second audio signals respectively comprises first and second noise content from a noise source; (ii) identifying the first noise content in the first audio signal; (iii) using the identified first noise content to determine an estimated noise content captured by the plurality of microphones; (iv) using the estimated noise content to suppress the first and second noise content in the first and second audio signals; (v) combining the suppressed first and second audio signals into a third audio signal; and (vi) determining that the third audio signal includes a voice input comprising a wake word.

A method for in-ear detection, the method may include transmitting test signals, by a speaker of an earbud, during a test period, and while the earbud is operating at a first operational mode, wherein the test signals comprise at least one first test signal within a first frequency range, at least one second test signal within a second frequency range, and at one third test signal within a third frequency range; wherein the first frequency range, the second frequency range and the third frequency range differ from each other and are within a human auditory range; generating, by a feedback microphone of the earbud, sensed information that is indicative of audio signals sensed by the feedback microphone as a result of the transmitting of the test signals; and determining whether the earbud is located within an ear of a person, wherein the determining is based on the sensed information and a reference out of ear spectrum.

An audio system comprises an array of transparent piezoelectric transducers on a transparent surface. Each transparent piezoelectric transducer includes one or more piezoelectric layers and one or more conductive layers that are substantially transparent to visible light. A transparent piezoelectric transducer may include, e.g., a first conductive layer, a first piezoelectric layer on the first conductive layer, and a second conductive layer on the first piezoelectric layer. Or in another example, the transparent piezoelectric transducer includes many (e.g., 20-30) piezoelectric layers and many (e.g., 20-30) conductive layers.

A transducer includes a base, beams, and a coupler. The beams each include a piezoelectric layer, a first electrode layer, and a second electrode layer. The coupler is fitted in slits between adjacent beams to define a connection between the beams. The coupler extends from an upper portion of the base into each of the slits without a break. A Young's modulus of the material of the coupler is lower than a Young's modulus of the material of the piezoelectric layer. A maximum thickness of the coupler in the upper portion of the base in the direction of the central axis of the base is greater than a thickness of each of the beams.

A processing device according to this embodiment includes: a measurement signal output unit configured to output a frequency sweep signal whose frequency is swept as a measurement signal; a sound pickup signal acquisition unit configured to acquire L-ch and R-ch sound pickup signals obtained by picking up the measurement signal by a left microphone and a right microphone; an evaluation signal acquisition unit configured to calculate an evaluation signal in a time domain in accordance with the L-ch and R-ch sound pickup signals; an extraction unit configured to extract a partial section of the evaluation signal as an extraction section; a comparison unit configured to compare the L-ch sound pickup signal with the R-ch sound pickup signal using the evaluation signal in the extraction section; and a determination unit configured to determine whether the fit of the right and left microphones or the output unit is good or not based on the results of the comparison made in the comparison unit.