A sound generator comprises a shell, a vibration system and a magnetic circuit system, wherein the shell sequentially accommodates and fixes the vibration system and the magnetic circuit system from top to bottom; the magnetic circuit system comprises a magnetic conductive yoke, and a central magnetic circuit portion and a side magnetic circuit portion that are mounted on an upper surface of the magnetic conductive yoke; a magnetic gap is formed between the central magnetic circuit portion and the side magnetic circuit portion; and at least one of the central magnetic circuit portion and the side magnetic circuit portion is provided with a permanent magnet; the magnetic circuit system is provided with a rear sound hole; a rear cavity in communication with the rear sound hole is provided directly below the magnetic circuit system.

Method and electronic circuit for determining a scaling factor k for a driving force function of a model of an electrodynamic acoustic transducer having at least two voice coils. Input signal fed into the transducer and it's model cause electromotive forces. A shift for the driving force function is determined on the base of the ratios between the real electromotive forces and the modeled electromotive forces. Finally, the scaling factor k is determined on the basis of a deviation between the real electromotive forces and the modeled electromotive forces at time points where the real electromotive forces and the modeled electromotive forces each are equal. The invention moreover relates to an electronic circuit for performing the above steps, and to a transducer system with the electronic circuit and a connected transducer.

Method and electronic circuit for determining a scaling factor k for a driving force function of a model of an electrodynamic acoustic transducer having at least two voice coils. Input signal fed into the transducer and it's model cause electromotive forces. A shift for the driving force function is determined on the base of the ratios between the real electromotive forces and the modeled electromotive forces. Finally, the scaling factor k is determined on the basis of a deviation between the real electromotive forces and the modeled electromotive forces at time points where the real electromotive forces and the modeled electromotive forces each are equal. The invention moreover relates to an electronic circuit for performing the above steps, and to a transducer system with the electronic circuit and a connected transducer.

An in-ear receiver can be used in a headset and/or hearing aid and includes a housing in which at least one ear canal section is configured to be inserted into an ear canal of a wearer when the in-ear receiver is used as intended. The housing defines at least one outer contour that is configured with at least in one section adapted to the ear canal of the wearer. The in-ear receiver includes a sound transducer arranged in the housing, and at least one resonant cavity, which is formed in the housing and is divided by the sound transducer into a front volume and a rear volume. The sound transducer is a MEMS sound transducer, and the front volume and/or the rear volume have/has an inner contour adapted to the ear canal.

A terminal device and a method for removing dust in a sound outlet hole of a loudspeaker are provided. The method includes the following: measuring a natural frequency of the loudspeaker, generating an audio file for removing dust according to the natural frequency, and prestoring the audio file for removing dust, wherein a vibration amplitude of a vibration diaphragm of the loudspeaker is at a maximum when the vibration diaphragm is driven to vibrates by an exciting current having the natural frequency; reading the prestored audio file for removing dust; and controlling the loudspeaker to play the audio file for removing dust, to generate air flow in the sound outlet hole, wherein when the loudspeaker plays the audio file for removing dust, a wind speed of the air flow through the sound outlet hole is at a maximum.

Provided is a notification device and notification method that reduce the output and power consumption of an amplifier or the like and allow a user to sufficiently feel the presence or absence of notification through vibration. A notification device (1) includes a sweep signal generator (4) configured to generate a detection sweep signal by continuously changing the frequency in a frequency band in which a speaker (6) can cause a user to feel a signal in the form of vibration, a vibration detector (7) configured to detect vibration outputted from the speaker (6), and a sound measurement unit (8) configured to detect, as a sweep frequency band, a frequency band in which vibration indicates signal levels equal to or higher than a threshold. The sweep signal generator (4) generates a resonance sweep signal by changing the frequency in the sweep frequency band and causes the speaker (6) to generate vibration.

Provided is a notification device and notification method that reduce the output and power consumption of an amplifier or the like and allow a user to sufficiently feel the presence or absence of notification through vibration. A notification device (1) includes a sweep signal generator (4) configured to generate a detection sweep signal by continuously changing the frequency in a frequency band in which a speaker (6) can cause a user to feel a signal in the form of vibration, a vibration detector (7) configured to detect vibration outputted from the speaker (6), and a sound measurement unit (8) configured to detect, as a sweep frequency band, a frequency band in which vibration indicates signal levels equal to or higher than a threshold. The sweep signal generator (4) generates a resonance sweep signal by changing the frequency in the sweep frequency band and causes the speaker (6) to generate vibration.

A vehicle is provided. The vehicle includes a speaker configured to output virtual sound to an outside of the vehicle and convert noise generated from the outside into energy and a battery configured to store the energy converted by the speaker.

A vehicle is provided. The vehicle includes a speaker configured to output virtual sound to an outside of the vehicle and convert noise generated from the outside into energy and a battery configured to store the energy converted by the speaker.

Disclosed is an acoustic transducer for converting a sound signal into an electric signal, including a mobile element movable under the effect of the sound signal, a fixed element opposite the mobile element, a recess, and a dissipative element between the mobile and fixed elements. The coupled system has a natural frequency corresponding to a resonance frequency of the transducer set at maximum sensitivity. The mobile element, the fixed element, the dissipative element and the recess are configured so the quality factor of the acoustic transducer>2. The recess has a straight prismatic, cylindrical, or frustoconical shape, the mobile element forming a first base of the prism, cylinder, or frustum, the fixed element being inside the prism, cylinder or frustum, over the second base of the prism, cylinder or frustum. Such a transducer also incorporates an analogue filtering function for filtering the signal around the natural frequency of same.