Abstract: A sample to be measured is placed in a medium solution between two circular magnets to ensure that the sample to be measured is levitated in a set circular area between the two circular magnets, and a levitation position of the sample to be measured in the magnetic field is measured. The density of the sample is calculated according to formula (I): ? s = ? m + ? m - ? s g ? ? 0 ? ( B r ? ? B z ? r + B z ? ? B z ? z ) . Compared to the prior art, the method of the present disclosure provides a novel method for measuring a density of a substance, in which the involved device is easy to operate and has low cost, and the measurement results are easy to observe and have high accuracy.

Abstract: The present disclosure discloses an acoustic device and a method for determining a transfer function thereof. The acoustic device includes a sound production unit, a first detector, a processor, and a fixing structure. The sound production unit is configured to generate a first sound signal based on a noise reduction control signal. The first detector is configured to obtain a first residual signal including a residual noise signal formed by superposition of an environmental noise and the first sound signal at a location of the first detector. The processor is configured to estimate a second residual signal at a target spatial location that is closer to the ear canal than the first detector, and update the noise reduction control signal based on the second residual signal. The fixing structure is configured to place the acoustic device at a location near a user's ear but not blocking the ear canal.

Abstract: A system for reducing noise for a user includes a first detector configured to generate a first noise signal, wherein the first noise signal is a representation of a first noise that is transmitted to the user through a first sound pathway, and a second detector configured to generate a second noise signal, wherein the second noise signal indicates a second noise perceived by the user. The system also includes a processor configured to determine a noise correction signal based on the first noise signal and/or the second noise signal, and a speaker configured to generate a sound for reducing the noise based on the noise correction signal.

Abstract: A noise reduction system is provided. The noise reduction system may include a sub-band noise sensor, a plurality of sub-band noise reduction modules, and an output module. The sub-band noise sensor may be configured to detect a noise and generate a plurality of sub-band noise signals in response to the detected noise. Each of the plurality of sub-band noise signals may have a distinctive sub-band of the frequency band of the noise. Each of the sub-band noise reduction modules may be configured to receive one of the sub-band noise signals from the sub-band noise sensor and generate a sub-band noise correction signal for reducing the received sub-band noise signal. The output module may be configured to receive the sub-band noise correction signals and output a noise correction signal for reducing the noise based on the sub-band noise correction signals.

Abstract: Microphone signals output by the microphone array satisfy a first model corresponding to a noise signal or a second model corresponding to a target voice signal mixed with a noise signal. A method and system may optimize the first model and the second model respectively by using maximization of a likelihood function and rank minimization of a noise covariance matrix as joint optimization objectives, and determine a first estimate of a noise covariance matrix of the first model and a second estimate of a noise covariance matrix of the second model; and determine, by using a statistical hypothesis testing method, whether the microphone signals satisfy the first model or the second model, so as to determine whether the target voice signal is present in the microphone signals, determine a noise covariance matrix of the microphone signals, and further perform voice enhancement on the microphone signals.

Abstract: A voice activity detection method and system and a voice enhancement method and system are provided. A voice presence probability of a target voice signal present in microphone signals may be determined by calculating a linear correlation between a signal subspace where the microphone signals are located and a target subspace where the target voice signal is located. The voice enhancement method and system may be used to calculate filter coefficients based on the voice presence probability, so as to perform voice enhancement on the microphone signals. The calculation accuracy of the voice presence probability is improved, and the voice enhancement effect is also improved.

Abstract: A system for reducing noise for a user includes a first detector configured to generate a first noise signal, wherein the first noise signal is a representation of a first noise that is transmitted to the user through a first sound pathway, and a second detector configured to generate a second noise signal, wherein the second noise signal indicates a second noise perceived by the user. The system also includes a processor configured to determine a noise correction signal based on the first noise signal and/or the second noise signal, and a speaker configured to generate a sound for reducing the noise based on the noise correction signal.

Abstract: A noise reduction system is provided. The noise reduction system may include a sub-band noise sensor, a plurality of sub-band noise reduction modules, and an output module. The sub-band noise sensor may be configured to detect a noise and generate a plurality of sub-band noise signals in response to the detected noise. Each of the plurality of sub-band noise signals may have a distinctive sub-band of the frequency band of the noise. Each of the sub-band noise reduction modules may be configured to receive one of the sub-band noise signals from the sub-band noise sensor and generate a sub-band noise correction signal for reducing the received sub-band noise signal. The output module may be configured to receive the sub-band noise correction signals and output a noise correction signal for reducing the noise based on the sub-band noise correction signals.

Abstract: The present disclosure provides a method for voice enhancement, including: obtaining a first signal and a second signal of a target voice, the first signal being a signal of the target voice collected based on a first position, and the second signal being a signal of the target voice collected based on a second position; determining a first coefficient by processing, based on a position of the target voice, the first position, and the second position, the first signal and the second signal; determining, based on the first signal and the second signal, a plurality of parameters related to a plurality of sound source directions; determining, based on the plurality of parameters and the position of the target voice, a second coefficient; and obtaining a voice-enhanced first output voice signal corresponding to the target voice by processing the first signal and/or the second signal.

Abstract: The present disclosure provides an acoustic device including a microphone array, a processor, and at least one speaker. The microphone array may be configured to acquire an environmental noise. The processor may be configured to estimate a sound field at a target spatial position using the microphone array. The target spatial position may be closer to an ear canal of a user than each microphone in the microphone array. The processor may be configured to generate a noise reduction signal based on the environmental noise and the sound field estimation of the target spatial position. The at least one speaker may be configured to output a target signal based on the noise reduction signal. The target signal may be used to reduce the environmental noise. The microphone array may be arranged in a target area to minimize an interference signal from the at least one speaker to the microphone array.

Abstract: The embodiments of the present disclosure provide a method and system for voice enhancement, including: obtaining a first signal and a second signal of a target voice, the first signal and the second signal being voice signals of the target voice at different voice collection positions; determining a target signal-to-noise ratio (SNR) of the target voice based on the first signal or the second signal; determining a processing mode for the first signal and the second signal based on the target SNR; and processing the first signal and the second signal based on the determined processing mode to obtain a voice-enhanced output voice signal corresponding to the target voice.

Abstract: An open acoustic device (100) may include a fixing structure (120) configured to fix the acoustic device (100) near an ear of a user without blocking an ear canal of the user; a first microphone array (130) configured to acquire environmental noise (410); a signal processor (140) configured to: determine, based on the environmental noise, a primary route transfer function (420) between the first microphone array (130) and the ear canal of the user; estimate, based on the environmental noise and the primary route transfer function, a noise signal (430) at the ear canal of the user; and generate, based on the noise signal at the ear canal of the user, a noise reduction signal (440); and a speaker (150) configured to output, according to the noise reduction signal, a noise reduction acoustic wave (450), the noise reduction acoustic wave being configured to eliminate the noise signal.

Abstract: The present disclosure provides a method and system for determining a speech presence probability, a speech enhancement method and system, and a headphone. The speech presence probability and a speech absence probability in an iteration operation may be corrected by comparing an entropy of the speech presence probability and an entropy of a speech absence probability, such that a faster convergence speed and better convergence results may be obtained, thereby improving accuracy of an estimation of the speech presence probability and an accuracy of an estimation of a noise spatial covariance matrix, and then improving a speech enhancement effect of a minimum variance distortionless response (MVDR).

Abstract: The present disclosure provides an active noise control audio device, method and storage medium. The device includes: a speaker, a microphone, an analog filter, and a processing circuit. The speaker used to generate a noise reduction sound; the microphone used to collect an environmental noise and the noise reduction sound and generate a first analog signal; the analog filter used to provide a gain for the first analog signal and to generate a second analog signal, the second analog signal driving the speaker to generate the noise reduction sound; and the processing circuit used to send a control instruction to the analog filter to adjust the gain and a phase shift of the analog filter according to the first analog signal and the second analog signal.

Abstract: The present disclosure provides an acoustic device including a microphone array, a processor, and at least one speaker. The microphone array may be configured to acquire an environmental noise. The processor may be configured to estimate a sound field at a target spatial position using the microphone array. The target spatial position may be closer to an ear canal of a user than each microphone in the microphone array. The processor may be configured to generate a noise reduction signal based on the environmental noise and the sound field estimation of the target spatial position. The at least one speaker may be configured to output a target signal based on the noise reduction signal. The target signal may be used to reduce the environmental noise. The microphone array may be arranged in a target area to minimize an interference signal from the at least one speaker to the microphone array.

Abstract: An open acoustic device (100) may include a fixing structure (120) configured to fix the acoustic device (100) near an ear of a user without blocking an ear canal of the user; a first microphone array (130) configured to acquire environmental noise (410); a signal processor (140) configured to: determine, based on the environmental noise, a primary route transfer function (420) between the first microphone array (130) and the ear canal of the user; estimate, based on the environmental noise and the primary route transfer function, a noise signal (430) at the ear canal of the user; and generate, based on the noise signal at the ear canal of the user, a noise reduction signal (440); and a speaker (150) configured to output, according to the noise reduction signal, a noise reduction acoustic wave (450), the noise reduction acoustic wave being configured to eliminate the noise signal.

Abstract: Embodiments of the present disclosure disclose an earphone including a fixing structure, a first microphone array, a processor, and a speaker. The fixing structure is configured to fix the earphone near a user's ear without blocking the user's ear canal and including a hook-shaped component and a body part. The first microphone array is located in the body part and is configured to pick up environmental noise. The processor is located in the hook-shaped component or the body part and is configured to estimate a sound field at a target spatial position using the first microphone array and generate a noise reduction signal based on the estimated sound field. The target spatial position is closer to the user's ear canal than any microphone in the first microphone array. The speaker is located in the body part and is configured to output a target signal according to the noise reduction signal.

Abstract: The present disclosure provides an acoustic device including a microphone array, a processor, and at least one speaker. The microphone array may be configured to acquire an environmental noise. The processor may be configured to estimate a sound field at a target spatial position using the microphone array. The target spatial position may be closer to an ear canal of a user than each microphone in the microphone array. The processor may be configured to generate a noise reduction signal based on the environmental noise and the sound field estimation of the target spatial position. The at least one speaker may be configured to output a target signal based on the noise reduction signal. The target signal may be used to reduce the environmental noise. The microphone array may be arranged in a target area to minimize an interference signal from the at least one speaker to the microphone array.

Abstract: The present disclosure discloses a magnetic flexible tactile sensor structure based on a folding magnetization method, which comprises a flexible body containing a permanent magnetic material; the flexible body has a negative Poisson's ratio structure, and its set area has undergone folding magnetization treatment. The present disclosure also discloses a sensor composed of the above-mentioned sensing structure. The sensor provided by the present disclosure can be applied in sealed and wireless scenarios. The present disclosure can detect the size and position of force. The flexible sensor has broad prospects in the application of the touch skin of robots. The function between the magnetic field-based sensing magnet and the Hall element is contactless. In some cases where it is difficult to establish isolation of the connection lines, it can also be used as an unfettered tactile sensor.

Abstract: A system for reducing noise for a user includes a first detector configured to generate a first noise signal, wherein the first noise signal is a representation of a first noise that is transmitted to the user through a first sound pathway, and a second detector configured to generate a second noise signal, wherein the second noise signal indicates a second noise perceived by the user. The system also includes a processor configured to determine a noise correction signal based on the first noise signal and/or the second noise signal, and a speaker configured to generate a sound for reducing the noise based on the noise correction signal.