An integrated circuit amplifier configurable to be either a programmable gain amplifier or an operational amplifier comprises two output blocks, one output block is optimized for programmable gain amplifier operation, and the other output block is optimized for operational amplifier applications. A common single input stage, input offset calibration and bias generation circuits are used with either amplifier configuration. Thus duplication of the input stage, offset calibration and bias generation circuits are eliminated while still selectably providing for either a programmable gain amplifier or operational amplifier configuration.

An ultrasonic audio system includes adaptive equalization techniques configured to adjust the overall output of the ultrasonic audio system. This can be done by adjusting the equalization of the electronic audio signal representing the audio content being reproduced by the ultrasonic audio system. For example, in various embodiments, systems and methods can be implemented to increase the gain of higher frequency portions of the electronic audio signal while making a corresponding decrease in the amount of gain at the lower frequency portions of the same signal.

An ultrasonic audio system includes adaptive equalization techniques configured to adjust the overall output of the ultrasonic audio system. This can be done by adjusting the equalization of the electronic audio signal representing the audio content being reproduced by the ultrasonic audio system. For example, in various embodiments, systems and methods can be implemented to increase the gain of higher frequency portions of the electronic audio signal while making a corresponding decrease in the amount of gain at the lower frequency portions of the same signal.

Techniques are disclosed for synchronizing gain adjustments across a cascaded network of audio gain stages having variant operating delays. In particular, a delay-synchronized volume adjustment system configured in accordance with an embodiment of the present disclosure includes a controller operatively coupled to the cascaded network of audio and configured to apply gain adjustments in a synchronized manner that accounts for operating delays that are inherent to each gain stage. In an embodiment, the controller synchronously adjusts each gain stage relative to a corresponding operating delay such that gain adjustments fully propagate at substantially a same point in time within a given acceptable tolerance, and thus, eliminates or otherwise mitigates perceivable volume shifts when mixing audio from two or more audio sources.

A digitally-controlled transimpedance amplifier (TIA) circuit is provided in which a plurality of feedback loops are digitally controlled, including, but not limited to, the DC offset cancellation loop, the variable gain control loop, and the TIA feedback impedance adjustment loop. The digitally-controlled TIA circuit includes digital loop-control circuitry that consumes less area on the TIA IC chip than the analog circuitry traditionally used to perform the feedback loop control in the analog domain. In addition, because digital logic continues to shrink as IC processes continue to evolve, the size of the IC chip packages will further decrease over time, leading to a smaller footprint in systems in which they are employed. The digital loop control circuitry is also capable of independently varying the gains of multiple gain stages of the variable gain control circuit to provide better control over the gain stages and better overall performance of the TIA circuit.

Devices, systems, and methods for multi-channel common-mode coupled alternating current (AC) gain amplifiers (MC-CM-AC Amp) are disclosed. The MC-CM-AC Amp can comprise a first operational amplifier including: a first non-inverting input port configured to be coupled to a first input signal, and a first inverting input port configured to be coupled to a first capacitor. The MC-CM-AC Amp can comprise a second operational amplifier including a second non-inverting input port configured to be coupled to a second input signal, and a second inverting input port configured to be coupled to a second capacitor. The MC-CM-AC Amp can comprise one or more gain-setting resistors configured to be coupled between the first capacitor and the second capacitor.

A reverberator for reverberating an audio signal includes a feedback delay loop processor for delaying at least two frequency subband signals representing the audio signal by different loop delays to obtain reverberated frequency subband signals.

A reverberant sound adding apparatus includes a noise generator configured to generate a noise, an impulse noise generator configured to generate an impulse noise comprising an impulse sequence with random time intervals, an addition noise generator configured to generate an addition noise by adding the noise to the impulse noise, an impulse response generator configured to generate a modified impulse response by multiplying the addition noise by an amplitude characteristic of an impulse response that indicates acoustic characteristics of a space, and an impulse response convolver configured to convolve an input audio signal with the modified impulse response.

A method comprising: displaying a spatio-temporal graph that visually indicates the positions of a sound object at each time in a range of times and, in addition, simultaneously indicates a state of the sound object over the range of times; enabling user adaptation of the spatio-temporal graph to change a position of the sound object during at least a portion of the range of times and/or a state of the sound object over at least a portion of the range of times; and enabling rendering of spatial audio output using the position and state of the sound object indicated by the adapted spatio-temporal graph.

An apparatus for generating a modified audio signal having two or more modified audio channels from an audio input signal comprising two or more audio input channels is provided. The apparatus has an information generator for generating signal-to-downmix information. The information generator is adapted to generate signal information by combining a spectral value of each of the two or more audio input channels in a first way. The information generator is adapted to generate downmix information by combining the spectral value of each of the two or more audio input channels in a second way being different from the first way. Furthermore, the information generator is adapted to combine the signal information and the downmix information to obtain signal-to-downmix information. The apparatus has a signal attenuator for attenuating the two or more audio input channels depending on the signal-to-downmix information to obtain the two or more modified audio channels.