Aspects of the subject technology relate to electronic devices having speakers such as microelectromechanical systems (MEMS) speakers. A MEMS speaker can include an electrostatically driven, corrugated MEMS structure to move air without a magnet, coil, or traditional speaker membrane, and thus provide a low-power, compact speaker with a large acoustically active area in a small volume. Neighboring folds in the corrugated MEMS structure may form pairs of MEMS electrodes that can be pushed together and/or pulled apart to deform the MEMS structure in a breathing motion that generates pressure differentials on opposing sides of the corrugated MEMS structure to generate sound. Additional modes of operation are described.

Aspects of the subject technology relate to electronic devices having speakers such as microelectromechanical systems (MEMS) speakers. A MEMS speaker can include an electrostatically driven, corrugated MEMS structure to move air without a magnet, coil, or traditional speaker membrane, and thus provide a low-power, compact speaker with a large acoustically active area in a small volume. Neighboring folds in the corrugated MEMS structure may form pairs of MEMS electrodes that can be pushed together and/or pulled apart to deform the MEMS structure in a breathing motion that generates pressure differentials on opposing sides of the corrugated MEMS structure to generate sound. Additional modes of operation are described.

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 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.

A control circuit for an electrostatic transducer including: an audio signal input, a detector configured to detect a current or charge signal from the electrostatic transducer. The detector is configured to produce an audio output signal varying at audio frequencies. A transform circuit is configured to transform the audio output signal to produce a feedback signal. A comparator is configured to compare an input audio signal at the audio signal input to the feedback signal to produce an error signal. A controller is configured to input a control signal to the electrostatic transducer, the control signal responsive to the error signal. The control signal is configured to control acoustic transparency of the electrostatic transducer, from outside space through through-holes of the first electrode, across the membrane and through through-holes of the second electrode.

A control circuit for an electrostatic transducer including: an audio signal input, a detector configured to detect a current or charge signal from the electrostatic transducer. The detector is configured to produce an audio output signal varying at audio frequencies. A transform circuit is configured to transform the audio output signal to produce a feedback signal. A comparator is configured to compare an input audio signal at the audio signal input to the feedback signal to produce an error signal. A controller is configured to input a control signal to the electrostatic transducer, the control signal responsive to the error signal. The control signal is configured to control acoustic transparency of the electrostatic transducer, from outside space through through-holes of the first electrode, across the membrane and through through-holes of the second electrode.

A loudspeaker arrangement for a plurality of MEMS loudspeakers for generating sound waves in the audible wavelength spectrum includes a housing, which has a sound conduction cavity and at least one sound outlet opening, and at least two MEMS loudspeakers, arranged in the interior of the housing opposite and spaced apart from each other by the sound conduction cavity. Each MEMS loudspeaker has a cavity in the region of their opposite faces. The loudspeaker arrangement includes a shielding wall for acoustically decoupling the two MEMS loudspeakers from each other. The shielding wall is arranged in the interior of the housing between the two MEMS loudspeakers such that the sound conduction cavity is subdivided into a first and a second a cavity region respectively associated with one of the two MEMS loudspeakers

A loudspeaker arrangement for a plurality of MEMS loudspeakers for generating sound waves in the audible wavelength spectrum includes a housing, which has a sound conduction cavity and at least one sound outlet opening, and at least two MEMS loudspeakers, arranged in the interior of the housing opposite and spaced apart from each other by the sound conduction cavity. Each MEMS loudspeaker has a cavity in the region of their opposite faces. The loudspeaker arrangement includes a shielding wall for acoustically decoupling the two MEMS loudspeakers from each other. The shielding wall is arranged in the interior of the housing between the two MEMS loudspeakers such that the sound conduction cavity is subdivided into a first and a second a cavity region respectively associated with one of the two MEMS loudspeakers

A novel system and method for spatial sound generation is disclosed. A system and method for generating bodiless mid-air speakers includes the steps of: generating a modulated signal by modulating an ultrasonic carrier signal with an audio signal, determining a phase delay value for each ultrasonic transducer of an array of ultrasonic transducers with respect to one or more focal points, and driving each such ultrasonic transducer with the modulated signal in accordance with the phase delay value determined for each ultrasonic transducer to generate audible sound at the one or more focal points.

An ultrasonic transducer having a reduced cost of manufacture. The ultrasonic transducer includes a first insulative retaining layer, a second insulative retaining layer, and a vibrator film layer sandwiched between the first and second retaining layers. The first retaining layer includes a first plurality of apertures formed therethrough, and the second retaining layer includes a second plurality of apertures formed therethrough, in which the second apertures are substantially in registration with the first apertures. The ultrasonic transducer further includes a first cover portion having a plurality of spring/backplate assemblies connected thereto, and a second cover portion. The combination of the first retaining layer, the vibrator film layer, and the second retaining layer is sandwiched between the first and second cover portions of the ultrasonic transducer. The laminated construction of the ultrasonic transducer allows the formation of an array of ultrasonic film transducers using a single piece of ultrasonic vibrator film.