A vibration sensor includes a vibration receiver and an acoustic transducer. The vibration receiver includes a housing and a vibration unit. The housing forms an acoustic cavity. The vibration unit is located in the acoustic cavity and divides the acoustic cavity into a first acoustic cavity and a second acoustic cavity. The acoustic transducer is acoustically connected to the first acoustic cavity. The housing is configured to generate vibration based on an external vibration signal. The vibration unit vibrates in response to the vibration of the housing and transmits, through the first acoustic cavity, the vibration to the acoustic transducer to generate an electrical signal. The vibrating unit includes a mass element and an elastic element. A deviation between cross-sectional areas of the mass element and the first acoustic cavity perpendicular to a vibration direction of the mass unit is less than 25%.

A vibration sensor includes a vibration receiver and an acoustic transducer. The vibration receiver includes a housing and a vibration unit. The housing forms an acoustic cavity. The vibration unit is located in the acoustic cavity and divides the acoustic cavity into a first acoustic cavity and a second acoustic cavity. The acoustic transducer is acoustically connected to the first acoustic cavity. The housing is configured to generate vibration based on an external vibration signal. The vibration unit vibrates in response to the vibration of the housing and transmits, through the first acoustic cavity, the vibration to the acoustic transducer to generate an electrical signal. The vibrating unit includes a mass element and an elastic element. A deviation between cross-sectional areas of the mass element and the first acoustic cavity perpendicular to a vibration direction of the mass unit is less than 25%.

A device for detecting the grip pattern when playing a bowed instrument, having a sensor film arrangeable on the fingerboard for detecting the grip pattern. The sensor film is formed from at least one resistance layer, a conductive layer and a spacer layer arranged in-between, and having an evaluation circuit, by which evaluation circuit the resistance changes of the sensor film caused by the grip pattern are able to be detected. The resistance layer is divided into a number of resistance tracks corresponding to the number of strings of the bowed instrument. The width of each resistance track is formed increasing from one end of the sensor film to the other end of the sensor film, and the upper layer of the sensor film is formed by the conductive layer, and the sensor film has a curvature, corresponding to the arch of the fingerboard.

A device for detecting the grip pattern when playing a bowed instrument, having a sensor film arrangeable on the fingerboard for detecting the grip pattern. The sensor film is formed from at least one resistance layer, a conductive layer and a spacer layer arranged in-between, and having an evaluation circuit, by which evaluation circuit the resistance changes of the sensor film caused by the grip pattern are able to be detected. The resistance layer is divided into a number of resistance tracks corresponding to the number of strings of the bowed instrument. The width of each resistance track is formed increasing from one end of the sensor film to the other end of the sensor film, and the upper layer of the sensor film is formed by the conductive layer, and the sensor film has a curvature, corresponding to the arch of the fingerboard.

A wearable stethoscope includes a sound sensing device for collecting heart sound signals of the body, an electrocardiogram sensing device for collecting electrocardiogram signals of the body, a processing unit, powered by a power source, coupled to the sound sensing device and the electrocardiogram sensing device to perform data preprocessing on the above-mentioned signals to remove background noise. An external electronic computing device is set up to analyze and process the fed pre-processed ECG signal and heart sound signal, perform feature extraction in combination with the user's physiological parameters and medical records to obtain related feature vectors, input the feature vectors into a screening model, obtain an evaluation value and give corresponding suggestions. After screening, users can upload the verification results to the cloud database to expand the existing training samples for further optimizing the parameters of the screening model.

A wearable stethoscope includes a sound sensing device for collecting heart sound signals of the body, an electrocardiogram sensing device for collecting electrocardiogram signals of the body, a processing unit, powered by a power source, coupled to the sound sensing device and the electrocardiogram sensing device to perform data preprocessing on the above-mentioned signals to remove background noise. An external electronic computing device is set up to analyze and process the fed pre-processed ECG signal and heart sound signal, perform feature extraction in combination with the user's physiological parameters and medical records to obtain related feature vectors, input the feature vectors into a screening model, obtain an evaluation value and give corresponding suggestions. After screening, users can upload the verification results to the cloud database to expand the existing training samples for further optimizing the parameters of the screening model.

The present invention comprises a device and process designed to accelerate the maturation of stringed musical instruments, composed of but not limited to a broad spectrum audio generator coupled with one or more fasteners via one or more armatures dimensioned to allow easy installation, secure attachment, and easy uninstallation from the stringed musical instrument.

The present invention comprises a device and process designed to accelerate the maturation of stringed musical instruments, composed of but not limited to a broad spectrum audio generator coupled with one or more fasteners via one or more armatures dimensioned to allow easy installation, secure attachment, and easy uninstallation from the stringed musical instrument.

Provided are an electroacoustic transduction film capable of reproducing a sound with a sufficient sound volume at a high conversion efficiency, a manufacturing method thereof, an electroacoustic transducer, a flexible display, a vocal cord microphone, and a sensor for a musical instrument. The electroacoustic transduction film includes: a polymer composite piezoelectric body in which piezoelectric body particles are dispersed in a viscoelastic matrix formed of a polymer material having viscoelasticity at a normal temperature; two thin film electrodes laminated on both surfaces of the polymer composite piezoelectric body; and two protective layers respectively laminated on the two thin film electrodes, in which an intensity ratio α.sub.1=(002) plane peak intensity/((002) plane peak intensity+(200) plane peak intensity) between a (002) plane peak intensity and a (200) plane peak intensity derived from the piezoelectric body particles in a case where the polymer composite piezoelectric body is evaluated by an X-ray diffraction method is more than or equal to 0.6 and less than 1.

Provided is to prevent a false determination due to an attachment condition of an apparatus that transmits and receives an acoustic signal, and perform accurate personal authentication. A personal authentication device includes: a personal authentication means that authenticates an individual by using first information at least including an acoustic characteristic calculated from an acoustic signal propagating through the head of the user, which is detected by an apparatus being attached on a head of a user for transmitting and receiving the acoustic signal, and a feature amount extracted from the acoustic characteristic; an attachment trouble rule storage means that stores an attachment trouble rule for detecting an attachment trouble with the apparatus; and an attachment trouble detection means that detects a trouble with an attachment state of the apparatus when the first information satisfies the attachment trouble rule.