The present disclosure relates to the technical field of earphone and provides to an active noise reduction earphone. The active noise reduction earphone includes an earphone shell, a speaker, a sound outlet mouth, a first feedback digital microphone, a second feedback digital microphone and a sound collecting channel. Herein, the speaker divides the earphone shell into the front speaker cavity and the back speaker cavity; the sound outlet mouth is arranged to be faced to the speaker to output the sound emitted by the speaker; the first feedback digital microphone is arranged at the first noise reduction sound collecting hole preset in the back speaker cavity to collect external ambient noise; the sound in the ear canal is collected through the sound collecting channel, and the second feedback digital microphone isolates the sound collecting channel from the front speaker cavity.

Defining critical spacing is necessary for steering of parametric audio. Comparing steering measurements both with and without a waveguide leads to a conclusion that the diffuse phyllotactic grating lobe contributes audio and is to blame for poor steering. In addition, the waveguide needs to function with correct phase offsets to achieve the steering required for performance. Arranging tubes so that the array configuration changes from rectilinear to another distribution is useful when the waveguide is short of critical spacing or constrained for space. Array designs may also capitalize on rectilinear transducer design while having the benefits of a transducer tiling that has irrational spacing to promote the spread of grating lobe energy.

A 1D ultrasonic transducer unit for detecting danger for a vehicle, comprising a housing mounted on the vehicle, which includes at least three discrete ultrasonic transducers, designed to decouple sound waves at a corresponding working frequency between 20 kHz and 400 kHz into a gaseous medium, and a control unit, designed to control each ultrasonic transducer individually, two ultrasonic transducers directly adjacent to each other in each case having a distance, the 1D ultrasonic transducer unit having one sound channel per ultrasonic transducer, each with one inlet opening assigned to exactly one ultrasonic transducer and one outlet opening (26), the outlet openings being arranged along a straight line, a distance from directly adjacent outlet openings corresponding to no more than the full or half wavelength in the gaseous medium and being shorter than the corresponding distance.

Embodiments for one-way sound absorbing systems are described herein. In one example, a sound absorbing system includes a waveguide having open ends for receiving an incoming acoustic wave and wall portions defining a first port and a second port. A first electroacoustic absorber is mounted to the first port and is electrically connected to a shunting circuit, while a second electroacoustic absorber is mounted to the second port and is electrically connected to an open circuit. The sound absorption of the system is directional dependent.

Defining critical spacing is necessary for steering of parametric audio. Comparing steering measurements both with and without a waveguide leads to a conclusion that the diffuse phyllotactic grating lobe contributes audio and is to blame for poor steering. In addition, the waveguide needs to function with correct phase offsets to achieve the steering required for performance. Arranging tubes so that the array configuration changes from rectilinear to another distribution is useful when the waveguide is short of critical spacing or constrained for space. Array designs may also capitalize on rectilinear transducer design while having the benefits of a transducer tiling that has irrational spacing to promote the spread of grating lobe energy.

A device for manipulating an incident acoustic wave to generate an acoustic output is described wherein the device comprises a plurality of unit cells arranged into an array, at least some of said unit cells being configured to introduce time delays to an incident acoustic wave at the respective positions of the unit cells within the array of unit cells, such that said plurality of unit cells define an array of time delays to thereby define a spatial delay distribution for manipulating an incident acoustic wave to generate an acoustic output. The array of time delays may be re-configured to vary the spatial delay distribution of the device in order to generate different acoustic outputs. Also described are methods for designing or configuring such devices.

A breakaway stethoscope includes a chest piece, a headset, a tube, and a coupler. The chest piece captures sounds generated inside a person's body when the chest piece is positioned adjacent the person's body. The headset directs the sounds captured by the chest piece toward a person's ear when the headset is positioned on an ear of the person. The tube connects the chest piece to the headset and conveys the sounds captured by the chest piece toward the headset. The tube has a length and includes a first portion connected to the chest piece and a second portion connected to the headset. The coupler releasably connects the tube's first portion to the tube's second portion and releases one of the tube's portions when the tube experiences a force that urges at least one of the tube's portions to move away from the coupler.

The present invention includes: a housing that includes an arrangement case in which an internal space is formed, and a sound guide tube in which a sound conduction space is formed; a feedback microphone to which an external sound is input; a first speaker unit that outputs a sound; and a second speaker unit that outputs a sound in an output band different from an output band of the sound output from the first speaker unit. The housing has inside a first space and a second space, the feedback microphone and the first speaker unit are arranged in the first space, the second speaker unit is arranged in the second space, and an equalizer that partitions the first space and the second space is disposed between the first speaker unit and the second speaker unit.

Embodiments of this application disclose a noise reduction headset. A branch pipe is disposed in the headset to connect a sound cavity inside the headset and an external environment. The branch pipe has a low-pass filter function to filter out high-band noise entering the sound cavity from the external environment, so that impact on sound quality inside the sound cavity that is caused by noise in the external environment is reduced, thereby implementing passive noise reduction.

A stethoscope includes a headset including a first eartube terminating in a first earpiece and a second eartube terminating in a second earpiece, and a chestpiece having a diaphragm. The stethoscope further includes flexible acoustic tubing having a first tubing segment connected to the headset and a second tubing segment connected to the chestpiece. The first tubing segment is manually disconnectable from the second tubing segment, and the first tubing segment is manually connectable to the second tubing segment to align and seal the first and second tubing segments and form an acoustic passageway extending from the chestpiece through the first and second tubing segments and the first and second eartubes to the first and second earpieces. Optionally, the flexible acoustic tubing with the disconnectable and connectable segments may be provided as a replacement component for a stethoscope.