An earphone includes a resonance circuit that outputs an adjusted signal obtained by making a signal component of a predetermined frequency contained in an electric signal outputted from a sound source device larger than a signal component of another frequency, a fixed electrode that is fixed to a housing, a diaphragm that is provided facing the fixed electrode and that vibrates according to a potential difference generated between the diaphragm and the fixed electrode on the basis of the adjusted signal, a contact part that contacts a partial region of the diaphragm and presses the partial region against the fixed electrode, and a sound emitting part that emits sound generated by vibration of the diaphragm to the outside of the housing.

The invention relates to audio transducers, such as loudspeaker, microphones and the like, and includes improvements in or relating to: audio transducer diaphragm structures and assemblies, audio transducer mounting systems; audio transducer diaphragm suspension systems, personal audio devices incorporating the same and any combination thereof. The embodiments of the invention include linear action and rotational action transducers. For both types of transducer, rigid and composite diaphragm constructions and unsupported diaphragm periphery designs are described. Systems and methods for mounting the transducer to a housing, such as an enclosure or baffle are also described. Furthermore, hinge systems including: rigid contact hinge systems and flexible hinge systems are also disclosed for various rotational action transducer embodiments. Various applications and implementations are described and envisaged for the audio transducer embodiments including, for example, personal audio devices such as headphones, earphones and the like.

Charged polymeric webs, such as electret webs, include a thermoplastic resin and a charge-enhancing additive. The additives are substituted heterocyclic thiolate salts. The heterocyclic thiolate salt has 2 nitrogen groups and a third group that may be an NH, N—NH.sub.2, O, or S group. The substituent group is an aromatic or heterocyclic aromatic group. The electret webs may be a non-woven fibrous web or a film. The electret webs are suitable for use as filter media.

The invention relates to audio transducers, such as loudspeaker, microphones and the like, and includes improvements in or relating to: audio transducer diaphragm structures and assemblies, audio transducer mounting systems; audio transducer diaphragm suspension systems, personal audio devices incorporating the same and any combination thereof. The embodiments of the invention include linear action and rotational action transducers. For both types of transducer, rigid and composite diaphragm constructions and unsupported diaphragm periphery designs are described. Systems and methods for mounting the transducer to a housing, such as an enclosure or baffle are also described. Furthermore, hinge systems including: rigid contact hinge systems and flexible hinge systems are also disclosed for various rotational action transducer embodiments. Various applications and implementations are described and envisaged for the audio transducer embodiments including, for example, personal audio devices such as headphones, earphones and the like.

Magnetic field cancelling audio systems and associated devices are disclosed. In one embodiment, an audio system with two electromagnetic audio drivers positioned and electrically connected to reduce emitted magnetic fields over a range of predefined frequencies.

An improved compact electroacoustic transducer and loudspeaker system. The electroacoustic transducer (or array of electroacoustic transducers) can generate the desired sound by the use of pressurized airflow. The electroacoustic transducer uses a shared stator with an array of vent support fingers and metal frame instead of two stators per electroacoustic transducer.

An energy conversion apparatus including a permanent magnet fixed to a predetermined region; and a diaphragm arranged on the permanent magnet, the diaphragm including a coil having a conductor wire pattern formed on the diaphragm, wherein the diaphragm includes a slit formed in the diaphragm.

An assembly of a transformer and an electrostatic sound generator is especially efficient if the resonance frequency of the diaphragm is in the frequency range in which the generator is operated, such as in the interval of 1-20 kHz. Then, a smaller transformer with a winding ratio of 5000 or less may be used for feeding the sound generator, making the assembly suitable for hearing aid purposes or in-ear products such as for pro audio use.

An electroacoustic transducer includes a first fixed electrode, a second fixed electrode, and a vibration body. The first and second fixed electrodes face each other across a space. The first fixed electrode includes first protrusions that are provided on a first electrode surface of the first fixed electrode and that protrude toward the second fixed electrode. The first protrusions are arranged at a first arrangement density that varies depending on a position of the first protrusions on the first electrode surface. The second fixed electrode includes second protrusions that are provided on a second electrode surface of the second fixed electrode and that protrude toward the first fixed electrode. The second protrusions are arranged at a second arrangement density that varies depending on a position of the second protrusions on the second electrode surface. The vibration body is sandwiched between the first protrusions and the second protrusions.

The present invention discloses a method for producing parametric sound using parametric sound system which is based on ultrasonic electrostatic transducers. It comprises modulation of a carrier ultrasonic signal with a processed audio signal in audio signal processor comprising adaptive frequency filtering based on the audio signal level, dynamic range compression, square root operation, amplification of the modulated ultrasonic signal using a D-class amplifier, driving an electrostatic transducer and generating modulated ultrasonic waves into the air. The electrostatic transducer for the parametric sound system comprises a specific back plate structure that improves electromechanical efficiency of the transducer and also enables realization of a phased array on a single back plate. The disclosed manufacturing method of the electrostatic transducer comprises producing sets of electrodes on the surface of the back plate forming individual cells.