The present invention relates to a diaphragm, and stethoscopes provided with the same. The diaphragm having a plate-shaped vibratable portion, and the vibratable portion has a first surface. The diaphragm further comprises a compliant structural layer disposed on the first surface. When the diaphragm is assembled with a sound collecting head, the compliant structural layer is in contact with the sound collecting head to enhance the airtightness between the diaphragm and the sound collecting head to prevent the acoustic vibration energy from dissipating. The invention also relates to methods for manufacturing the diaphragm which can quickly produce a large number of diaphragms by simple processes.

A polymer resin film of the present disclosure has a plurality of through holes extending through the thickness of the polymer resin film. The through holes penetrate a substrate structure of the resin film. The through holes have openings formed in both a first principal surface and a second principal surface of the film. The through holes have a shape in which the area of a cross-section perpendicular to a direction in which the through holes extend is constant from the first principal surface of the film to the second principal surface of the film or increases from the first principal surface toward the second principal surface. The openings in the first principal surface have a diameter of 3 m or more and 80 m or less. A variation in a porosity defined by the openings in the first principal surface is 10% or less.

As a base material, a plate-shaped member made of a metal, a ceramic, or the like is used, and dense portion provided in a propagation direction of the sound wave, and depressed portions are provided, the depressed portions being partially provided in vibration surface of the base material having a plate shape toward joining surface that is in a propagation direction of a sound wave. This configuration reduces an acoustic impedance, and allows transmission of the sound wave to a gas to be efficiently performed. Furthermore, since dense portion where the sound wave is propagated has a high density, an acoustic transmission loss is small, and excellent characteristics as an acoustic matching layer can be obtained.

As a base material, a plate-shaped member made of a metal, a ceramic, or the like is used, and dense portion provided in a propagation direction of the sound wave, and depressed portions are provided, the depressed portions being partially provided in vibration surface of the base material having a plate shape toward joining surface that is in a propagation direction of a sound wave. This configuration reduces an acoustic impedance, and allows transmission of the sound wave to a gas to be efficiently performed. Furthermore, since dense portion where the sound wave is propagated has a high density, an acoustic transmission loss is small, and excellent characteristics as an acoustic matching layer can be obtained.

A vehicle computing system may implement techniques to dynamically adjust a volume and/or frequency of a sound emitted from a vehicle to warn an object (e.g., dynamic object) of a potential conflict with the vehicle. The techniques may include determining a baseline noise level and/or frequencies proximate to the object. The baseline noise level and/or frequencies may be determined based on an identification of one or more noise generating objects in the environment. The vehicle computing system may determine the volume and/or a frequency of the sound based in part on the baseline noise level and/or frequencies, an urgency of the warning, a probability of conflict between the vehicle and the object, a speed of the object, etc.

A vehicle computing system may implement techniques to dynamically adjust a volume and/or frequency of a sound emitted from a vehicle to warn an object (e.g., dynamic object) of a potential conflict with the vehicle. The techniques may include determining a baseline noise level and/or frequencies proximate to the object. The baseline noise level and/or frequencies may be determined based on an identification of one or more noise generating objects in the environment. The vehicle computing system may determine the volume and/or a frequency of the sound based in part on the baseline noise level and/or frequencies, an urgency of the warning, a probability of conflict between the vehicle and the object, a speed of the object, etc.

One-way sound transmission devices include a planar, acoustically reflective substrate having an aperture that is traversed by an elastic membrane. On one face of the substrate, two resonators are symmetrically spaced apart from the membrane at a first distance, configured to enable constructive interference between the resonators and the membrane. On the opposite face of the substrate, two other resonators are symmetrically spaced apart from the membrane at a second, greater, distance, configured to enable destructive interference between the resonators and the membrane.

One-way sound transmission devices include a planar, acoustically reflective substrate having an aperture that is traversed by an elastic membrane. On one face of the substrate, two resonators are symmetrically spaced apart from the membrane at a first distance, configured to enable constructive interference between the resonators and the membrane. On the opposite face of the substrate, two other resonators are symmetrically spaced apart from the membrane at a second, greater, distance, configured to enable destructive interference between the resonators and the membrane.

A sensor system for a wind turbine, comprising: a blade load sensor; a blade temperature sensor configured to provide a temperature measurement of an associated blade; a load calculation module configured to output a temperature-corrected blade load value; and a processing unit interfaced with the temperature sensor. The processing unit includes a temperature estimator configured to determine an estimated temperature of the wind turbine blade based on at least one wind turbine parameter; and a comparator configured to generate a fault signal based on a comparison between the blade temperature measurement and the estimated blade temperature. The invention also resides in a corresponding method.

A Piezoelectric Micromachined Ultrasonic Transducer (PMUT) device includes a substrate, an edge support structure connected to the substrate, and a membrane connected to the edge support structure such that a cavity is defined between the membrane and the substrate, the membrane configured to allow movement at ultrasonic frequencies, the membrane having non-uniform stiffness. The membrane includes a piezoelectric layer, a first electrode and a second electrode coupled to opposing sides of the piezoelectric layer, and a mechanical support layer coupled to one of the first electrode and the second electrode.