In a first aspect, the invention relates to a system comprising a MEMS microphone comprising a sound inlet opening, a vibratable microphone membrane and an electronic circuit, wherein when the microphone membrane is excited by sound waves entering through the sound inlet opening, an electrical signal that is dependent on the sound waves is generated by vibrations of the microphone membrane. A damping element for reducing the sound pressure level of the sound waves acting on the microphone membrane is mounted in front of the sound inlet opening, wherein the damping element comprises an elastic and vibratable damping membrane and wherein, in addition to the microphone membrane, the damping element is induced into vibrations by the sound waves such that the sound energy of the sound waves is divided between the damping membrane and the microphone membrane. This makes it possible in particular to extend the measuring range of the MEMS microphone without distortion to high sound pressure levels that could not previously be measured with the MEMS microphones known in the prior art.

In a further aspect, the invention relates to the use of the system according to the invention for aeroacoustic measurements, preferably for measuring sound pressure waves on surfaces of a vehicle component.

An assembly of at least one radiation detector, at least one radiation emitter and a housing configured to be positioned inside the ear canal of a person or animal, the detector(s) and emitter(s) being provided in or on the housing, the emitter(s) being configured to emit radiation away from the housing and the detector(s) being configured to receive radiation directed toward the housing. No overlap may be provided between the field of view of the radiation detector(s) and the emitter(s), such as by providing a blocking element.

This application describes an apparatus (300) for monitoring for blockage of an acoustic (110) port of a microphone device (100). The apparatus has a spectrum peak detect block (301) for receiving a microphone signal (S.sub.MIC) and determining, from the microphone signal, a resonance frequency (f.sub.H) and a quality factor (Q.sub.H) of a resonance (202) associated with the acoustic port. A condition monitoring block (302) is configured to determine any change in resonance frequency and quality factor and to determine a blockage status for the microphone based on said detect changes. The condition monitoring block identifies a change in blockage status if there is a change in quality factor.

This application describes a noise reduction apparatus (800) for a microphone device (100) having an acoustic port (110). The apparatus has a spectrum peak detect block (301) for receiving a microphone signal (S.sub.MIC) and determining, from the microphone signal, at least one characteristic of a resonance peak (202) associated with the acoustic port of the microphone. The at least one characteristic may comprise a resonance frequency (f.sub.H) and/or quality factor (Q.sub.H). A noise reduction block (801) is configured to process the microphone signal based on the resonance characteristic so as to reduce noise in the processed microphone signal due to said resonance. The noise reduction block may apply a function which is the inverse of the determined resonance characteristic.

A detecting device 100 detects an elastic wave propagating through the air. The detecting device100 includes: a first electrode 12 that is a plate having a cantilever structure with a fixed end FX and a free end FR and that vibrates by being bent by the elastic wave; and a second electrode 32 that is a plate, that is opposed to the first electrode, and that has a predetermined distance from the first electrode. The detecting device 100 detects the elastic wave on the basis of a change in capacitance between the first electrode and the second electrode 32. An end of the second electrode 32 in a direction from the fixed end FX to the free end FR is closer to the fixed end than the free end.

An acoustic device with a housing with a central portion and first and second leg portions that depend from the central portion, a first acoustic driver carried by the first leg portion, a second acoustic driver carried by the second leg portion, and an audio signal control system that directs audio signals to each of the first and second drivers, where the drivers transduce the audio signals to output sounds. The audio signal control system is arranged to apply first and second equalization modes to the audio signals in a first and second listening mode, respectively. The second equalization de-emphasizes frequencies below a first threshold frequency and boosts frequencies above the first threshold frequency.

Holographic sound is recorded and reproduced by way of a single monaural recording per left and right ear recorded. This is accomplished by determining the phase shift of frequencies recorded after dividing the sound into discrete frequencies in a recording device having resonators, each resonating at a different frequency, placed in a circular arrangement and divided into discrete channels by non-resonant material. The resonators are placed in a pseudo-randomized arrangement within the recording device and the circle of resonators is in front of a microphone which records the sound monaurally. Playback is then by way of arranging speakers or transducers into micro perforated sheets which amplify the sound, the arrangement of speakers/transducers around a central point. The sound is then played back directionally based on the position where the sound originally was recorded from and the position of the particular transducer around the central point.

An acoustic device that has a neck loop that is constructed and arranged to be worn around the neck. The neck loop includes a housing with a first acoustic waveguide having a first sound outlet opening, and a second acoustic waveguide having a second sound outlet opening. There is a first open-backed acoustic driver acoustically coupled to the first waveguide and a second open-backed acoustic driver acoustically coupled to the second waveguide.

A camera includes one or more microphone pairs. A first microphone (e.g., a main microphone) is ported to the outside of the camera and captures the desired external audio signal, but may also capture undesired vibrational noise. A second microphone has a similar structure to the first microphone, but is not ported to the outside of the camera. Instead, the second microphone is ported into an enclosed cavity (e.g., 1-2 cubic centimeters in volume). The second microphone may pick up the same vibration excitation and internal acoustic noise as the first microphone but very little of the desired external acoustic sounds around the camera. The unwanted noise can then be removed by subtracting the second audio signal from the second microphone from the main audio signal from the main microphone.

An acoustic device that has a neck loop that is constructed and arranged to be worn around the neck. The neck loop includes a housing with a first acoustic waveguide having a first sound outlet opening, and a second acoustic waveguide having a second sound outlet opening. There is a first open-backed acoustic driver acoustically coupled to the first waveguide and a second open-backed acoustic driver acoustically coupled to the second waveguide.