The present disclosure provides a detection system and a detection method. The microphone of the detection system receives the response signal formed according to the shape of the sealed cavity. The conversion unit transfers the response signal in the time domain to the frequency domain signal in the frequency domain. The calculation unit obtains every frequency value corresponding to the frequency gradient being zero of each frequency waveform which is chosen of the response signal. The average unit averages every frequency value corresponding to the frequency gradient being zero of each chosen frequency waveform into the average frequency value and outputs an average frequency value. The determination unit determines whether the average frequency value is located in the corresponding frequency tolerance range, so that the wearing status of the in-ear earphone is confirmed.

The present disclosure provides a detection system and a detection method. The microphone of the detection system receives the response signal formed according to the shape of the sealed cavity. The conversion unit transfers the response signal in the time domain to the frequency domain signal in the frequency domain. The calculation unit obtains every frequency value corresponding to the frequency gradient being zero of each frequency waveform which is chosen of the response signal. The average unit averages every frequency value corresponding to the frequency gradient being zero of each chosen frequency waveform into the average frequency value and outputs an average frequency value. The determination unit determines whether the average frequency value is located in the corresponding frequency tolerance range, so that the wearing status of the in-ear earphone is confirmed.

A hybrid pulse compression RF system is provided herein in which an enhanced noise waveform and a hybrid waveform are generated to detect a target. For example, the system includes a signal generator that generates an LFM waveform and an enhanced waveform in sequence such that a transmitter of the system transmits the waveforms in the generated sequence in a direction of a possible target. The enhanced waveform may be a partially randomized version of the LFM waveform. If a target is present, the waveforms reflect off the target and are captured by the system in the sequence in which the originally generated waveforms are transmitted. Once captured, the reflected waveforms are processed by the system to generate a hybrid waveform for display such that the range and Doppler resolution and detection capabilities are significantly superior to the state of the art LFM or noise waveform RF systems.

An air-coupled ultrasonic interferometric method is disclosed. An air-coupled ultrasonic transducer, as a probe, is placed directly facing the surface of a workpiece, and an ultrasonic wave is reflected back and forth between the ultrasonic transducer and the surface of the workpiece; the phase difference of the first echo reflected from the surface of the workpiece and reaching the air-coupled ultrasonic transducer is measured; based on the change of the ultrasonic frequency and wavelength, the measured distance is transformed into the rate of change of the acoustic phase with respect to the acoustic angular frequency, wherein the change in the acoustic angular frequency is a product obtained by multiplying 2π by the difference between the highest frequency F2 and the lowest frequency F1 within the bandwidth fB of the air-coupled ultrasonic transducer.

An air-coupled ultrasonic interferometric method is disclosed. An air-coupled ultrasonic transducer, as a probe, is placed directly facing the surface of a workpiece, and an ultrasonic wave is reflected back and forth between the ultrasonic transducer and the surface of the workpiece; the phase difference of the first echo reflected from the surface of the workpiece and reaching the air-coupled ultrasonic transducer is measured; based on the change of the ultrasonic frequency and wavelength, the measured distance is transformed into the rate of change of the acoustic phase with respect to the acoustic angular frequency, wherein the change in the acoustic angular frequency is a product obtained by multiplying 2π by the difference between the highest frequency F2 and the lowest frequency F1 within the bandwidth fB of the air-coupled ultrasonic transducer.

A method for determining a change in a distance, a location prompting method and an apparatus and a system thereof are provided. The method includes: sending, by a receiving terminal, a paring request to a server for the server to forward the paring request to a transmitting terminal, and to allocate a frequency band for the receiving terminal and the transmitting terminal after the transmitting terminal accepts the paring request; acquiring, by the receiving terminal, an acoustic wave signal of a frequency sent by the transmitting terminal, wherein the frequency is determined by the transmitting terminal based on the allocated frequency band; determining, by the receiving terminal, a change in the acquired acoustic wave signal; and determining, by the receiving terminal, a change in a distance between the transmitting terminal and the receiving terminal according to the change in the acquired acoustic wave signal.

A method for determining a change in a distance, a location prompting method and an apparatus and a system thereof are provided. The method includes: sending, by a receiving terminal, a paring request to a server for the server to forward the paring request to a transmitting terminal, and to allocate a frequency band for the receiving terminal and the transmitting terminal after the transmitting terminal accepts the paring request; acquiring, by the receiving terminal, an acoustic wave signal of a frequency sent by the transmitting terminal, wherein the frequency is determined by the transmitting terminal based on the allocated frequency band; determining, by the receiving terminal, a change in the acquired acoustic wave signal; and determining, by the receiving terminal, a change in a distance between the transmitting terminal and the receiving terminal according to the change in the acquired acoustic wave signal.

A wireless audio system configured to perform an acoustic ranging operation is disclosed. The audio system comprises an audio transmitter, and audio receiver, and is configured to determine a distance between the audio transmitter and the audio receiver.

A wireless audio system configured to perform an acoustic ranging operation is disclosed. The audio system comprises an audio transmitter, and audio receiver, and is configured to determine a distance between the audio transmitter and the audio receiver.

The present disclosure provides a detection system and a detection method. The microphone of the detection system receives the response signal formed according to the shape of the sealed cavity. The conversion unit transfers the response signal in the time domain to the frequency domain signal in the frequency domain. The calculation unit obtains every frequency value corresponding to the frequency gradient being zero of each frequency waveform which is chosen of the response signal. The average unit averages every frequency value corresponding to the frequency gradient being zero of each chosen frequency waveform into the average frequency value and outputs an average frequency value. The determination unit determines whether the average frequency value is located in the corresponding frequency tolerance range, so that the wearing status of the in-ear earphone is confirmed.