Disclosed is a frequency characteristic adjusting circuit disposed between an optical circuit element and a drive circuit driving the optical circuit element. The frequency characteristic adjusting circuit includes a capacitor, and two or more series circuits having a resistor and a switch, the two or more series circuits being connected in parallel with the capacitor, where resistance with respect to the switch that is turned on is changed according to an output voltage of the drive circuit by changing ON or OFF of the switch such that electric charge at a contact point between the optical circuit element and the capacitor is adjusted to be constant regardless of the output voltage of the drive circuit.

A sound reproduction device includes a signal processing chain configured to render an acoustic useful signal for reproduction to a listener, a simulation scenario processor configured to provide auditory scenario information for a simulated auditory scenario, the simulated auditory scenario influencing perception, by the listener, of the reproduction of the useful signal and/or defining a useful signal type, a user interface configured to detect reproduction parameter settings from a user which represent an individual preference of the listener in view of the simulated auditory scenario, a signal modifier configured to receive the reproduction parameter settings and modify reproduction of the useful signal in dependence on the reproduction parameter settings, and a storage provided for storing the reproduction parameter setting and the auditory scenario information relative to one another. Further aspects relate to a method for training user-defined and auditory scenario-dependent reproduction parameter settings for a sound reproduction device, and a corresponding computer program.

Systems and methods to provide an audio spectral correction can be implemented in a variety of applications. Such systems and methods can include an equalizer design that uses efficient filter sections tuned with a closed form algorithm to give an accurate and intuitive frequency response with low complexity and minimal processing overhead. Embodiments can enable efficient and accurate control of reverberation time vs. frequency in artificial reverberators. Embodiments can enable efficient realization of a cascade combination of multi-band equalization functions as a single multi-band equalizer function, in which such functions can be expressed as graphic equalization functions using the same set of center frequencies as the cascade combination of multi-band equalization functions. Additional apparatus, systems, and methods are disclosed.

A measurement method of this disclosure is for evaluating an electronic device (100) that transmits air-conducted sound, generated by vibration of a vibrating body (102), to a user by the vibrating body (102) being placed in contact with a human ear. The measurement method includes placing the vibrating body (102) in contact with an ear model unit (50), measuring air-conducted sound generated by the electronic device (100) and air-conducted sound generated in the ear model unit (50), and selecting a correction value from among a plurality of correction values.

An audio system includes a loudspeaker cabinet defining a longitudinal axis. Several loudspeaker transducers are distributed around the longitudinal axis. The audio system includes an audio rendering processor to cause the loudspeaker transducers to emit a sound field approximating a desired contour. The desired contour can be decomposed into a combination of several constituent modal beam components, and the audio rendering processor can render a truncated version of the decomposition to render an approximation of the desired contour. The desired contour can be one of a plurality of contours stored in a memory, or can be user defined. The cabinet includes a processor and a memory having instructions that, when executed by the processor, cause the audio system decompose a desired contour and to render a truncated version of the decomposition. Related principles are described by way of reference to method and apparatus examples.

A circuit and method is disclosed for filtering an audio signal. The circuit has a first quadrature source and multipliers for multiplying the input signal by the I and Q outputs of the quadrature source. The multiplied inputs are then passed through a pair of low pass filters, which may have an adjustable Q factor. The outputs of the low pass filters are then multiplied in a second pair of multipliers by the I and Q outputs, respectively, of a second quadrature source, which will typically be of the same frequency, but different amplitude and phase, of the first quadrature source. The twice-multiplied signals are then summed by an adder to provide an output signal. The circuit may be modified to include a companding circuit between the low pass filters and the second pair of multipliers that determines the amplitude of the input signal, filters it, and compands the signal in a compandor. The compandor may have adjustable parameters. The circuit thus allows for far greater flexibility and control of the processing of the input signal than prior art circuits.

For detecting and resolving bad audio during conferencing, methods, apparatus, and systems are disclosed. One apparatus includes a processor and a memory that stores code executable by the processor. The processor detects bad audio for a conference call, the conference call involving a plurality of participants. The processor switches a first input stream to an analysis mode, where the bad audio corresponds to a first one of a plurality of input streams, the first input stream associated with a first participant. The processor sends a conference output channel to the first participant while in the analysis mode and concurrently analyzes the first input stream using a plurality of audio tools while in the analysis mode. The processor returns the first input stream to a conferencing mode in response to resolving the bad audio.

Systems, methods, and computer hardware storage media are provided for variably reducing, but not eliminating, the ambient volume that reaches the eardrum in a particular setting. One or more noise signatures of sound from an ambient environment are received at a mobile device. A profile associated with a suppression or amplification control of the one or more noise signatures of sound from the ambient environment are created and stored at the mobile device. The suppression or amplification control is communicated from the mobile device to a set of variable audio ear plugs. The suppression control causes the variable audio ear plugs to variably reduce, but not eliminate, the sound from the ambient environment and the amplification control does not amplify sound from any source other than the ambient environment.

An electronic audio device has a microchip has embedded therein, circuitry for enhancing the sound outputted therefrom and which is associated, such as a radio, television, headphones, earbuds and the like.

Each input channel adjusts a level of an audio signal by individual first parameters and outputs the level-adjusted audio signals to individual output routes that include bus channels. Each bus channel mixes the level-adjusted audio signals and processes the mixed audio signal by a second parameter to output to a main output. A preview channel adjusts a level of the audio signal of each of input channels by a third parameter, mixes the level-adjusted audio signals of the input channels and processes the mixed audio signal by a fourth parameter to output to a monitor output. In response to a preview instruction, the first parameter of the input channel is copied as the third parameter, and the second parameter of the bus channel is copied as the fourth parameter of the preview channel. In response to an adjustment instruction, the third or fourth parameter of the preview channel is changed.