Signal energy in auditory sub-bands of an input audio signal is determined. Sound pressure level, SPL, in those sub-bands is then determined, based on the signal energy and based on sound output sensitivity of the against-the-ear audio device. In one instance, at least first and second gain lookup tables are determined based on a hearing profile of a user of the against-the-ear audio device. Sub-band gains that are to be applied to the input audio signal are determined based on the determined SPL. When the input audio signal is for example telephony the sub-band gains are computed using the first gain lookup table, and when the input audio signal is for example media the sub-band gains are computed using the second gain lookup table. Other aspects are also described and claimed.

Provided is a preamplifying circuit, including a first amplifier and a second amplifier sequentially connected in series, wherein an output end of the second amplifier is connected to a circuit output end, and an input end of the first amplifier is connected to a circuit input end. The preamplifying circuit further includes a positive feedback branch including a diode group and a third amplifier, wherein one end of the diode group is connected to the input end of the first amplifier. The positive feedback circuit can positively feed part of signals back to the other end of the diode group, so that voltage drops at two ends of the diode group can be reduced, and harmonic distortion caused by nonlinearity of the diode group is reduced. Thus, the sound quality detected by a microphone sensor is improved.

Methods and apparatus to determine automated gain control parameters for an automated gain control protocol are disclosed. An example apparatus includes a first tuner to amplify an audio signal. Disclosed example apparatus also include a second tuner to amplify the audio signal. Disclosed example apparatus also include a first controller to tune the first tuner to apply a first gain representative of a first range of gains to the audio signal to determine a first amplified audio signal and tune the second tuner to apply a second gain representative a second range of gains to the audio signal to determine a second amplified audio signal, the second range of gains lower than the first range of gains. Disclosed example apparatus also include a second controller to select the first range of gains to be utilized in an automated gain control protocol when the first gain results in clipping of the first amplified audio signal and the second gain does not result in clipping of the second amplified audio signal.

In some embodiments, a method for processing an audio signal in an audio processing apparatus is disclosed. The method includes receiving an audio signal and a parameter, the parameter indicating a location of an auditory event boundary. An audio portion between consecutive auditory event boundaries constitutes an auditory event. The method further includes applying a modification to the audio signal based in part on an occurrence of the auditory event. The parameter may be generated by monitoring a characteristic of the audio signal and identifying a change in the characteristic.

A speaker excursion characterizing system for a speaker includes a signal generator configured to generate a signal at a plurality of different amplitudes. The signal may be generated at a plurality of frequencies. An inverse excursion filter has an inverse excursion filter response, receives the signal and applies the inverse excursion filter response and has an output in communication with an amplifier circuit of the speaker. The inverse excursion filter response is an inverse of an excursion filter response of an excursion filter in the amplifier circuit of the speaker.

A signal processing device includes a first panel displacement control unit to which a first audio signal is input, a second panel displacement control unit to which a second audio signal is input, and a control unit configured to control the first panel displacement control unit and the second panel displacement control unit. The first panel displacement control unit includes a first gain adjustment unit configured to adjust a level of the first audio signal, the second panel displacement control unit includes a second gain adjustment unit configured to adjust a level of the second audio signal, and the control unit includes a correlation determination unit configured to determine presence or absence of a correlation between the first audio signal and the second audio signal, and a gain control unit configured to control a level adjustment amount in each of the first gain adjustment unit and the second gain adjustment unit on the basis of a determination result of the correlation determination unit.

In-ear sound pressure level, SPL, is determined that is caused by output audio being converted into sound by a headset worn by a user. The in-ear SPL is converted into a sound sample having units that are suitable for evaluating sound noise exposure. These operations are repeated to produce a sequence of sound samples during playback. This sequence of sound samples is then written to a secure database. Access to the database is authorized by the user. Other aspects are also described and claimed.

An electronic device and method that automatically adjusts an audio output volume level based on a live environmental acoustic scenario input via a microphone using a machine learning algorithm trained with Human Activity Recognition (HAR). Equipped with such an intelligence the electronic device classifies ambient sounds occurring in the environment of the listening area in which the device is situated into different acoustic scenario mappings such a voice or conversation, for an ambient human conversation detected event, and noise, such as for example a vacuum cleaner or dish washer noise detected event, and automatically adjust the audio output volume accordingly.

The present disclosure relates to circuitry for driving a piezoelectric transducer. The circuitry comprises amplifier circuitry configured to receive a drive signal and to output an output signal, based on the drive signal, to the piezoelectric transducer, a variable capacitor configured to be coupled in series with the piezoelectric transducer, and control circuitry. The control circuitry is configured to control a capacitance of the variable capacitor to compensate for hysteresis in the piezoelectric transducer and to control a gain of the amplifier circuitry to compensate for signal attenuation caused by the variable capacitor.

This invention provides compact Power Amplifiers with improved efficiency of the circuitry and improved heat dissipation, together achieved much smaller enclosure size for use in modern installations requiring reduced height such as between the thin flat TV and wall, under the table or on the projector pole or in ceiling box and the like.