Example techniques may provide volume enhancements to a media playback system. An example implementation involves a first playback device in a first playback configuration playing audio at a first volume level and storing the first volume level in association with the first playback configuration. The first playback device receives instructions to change to a second playback configuration. Based on receiving the instructions, the first playback device joins a synchrony group with a second zone and adjusts the first playback device to play audio at a second volume level which is based on a volume level of a second playback device in the second zone. While in the second playback configuration, the first playback device receives instructions to change to the first playback configuration and, based on the instructions, leaves the synchrony group and adjusts the first playback device to play audio content at the stored first volume level.

A method for dynamically controlling enhancement of an audio stream is provided, where the audio stream defines a sequence of audio segments over time. Each audio segment defines a waveform having a plurality of waveform attributes. For each audio segment of the sequence of audio segments, the method includes: (i) determining a set of waveform-attribute values of the audio segment's waveform attributes, (ii) computing a first distance between the determined set of waveform-attribute values and a first predefined set of waveform-attribute values representative of speech, and computing a second distance between the determined set of waveform-attribute values and a second predefined set of waveform-attribute values representative of music, (iii) using the computed first and second distances as a basis to classify the audio segment as primarily speech or rather primarily music, and (iv) controlling, based on the classifying, whether or not to enhance the audio segment for output.

In one aspect, an example method includes (i) determining, by a playback device, a first loudness level of a first portion of first media content from a first source while the playback device presents the first media content, with the first portion having a first length; (ii) switching, by the playback device, from presenting the first media content from the first source to presenting second media content from a second source; (iii) based on the switching, determining, by the playback device, second loudness levels of second portions of the first media content while the playback device presents the second media content, with the second portions having a second length that is shorter than the first length; and (iv) while the playback device presents the second media content, adjusting, by the playback device, a volume of the playback device based on one or more of the second loudness levels.

Methods and apparatus to perform an automated gain control protocol with an amplifier based on historical data corresponding to contextual data are disclosed. An example apparatus includes a controller to select an automatic gain control (AGC) parameter for an AGC protocol based on historical data corresponding to contextual data, the contextual data including at least one of a time during which the AGC protocol is performed, a panelist identified by a meter, demographics of an audience identified by the meter, a location of the meter, a station identified by the meter, a media type identified by the meter, or a sound pressure level identified by the meter; and a processor to perform the AGC protocol based on the selected AGC parameter.

System and methods for accuracy improvement of an LVDT are provided. Aspects include determining a first voltage from the first PGA and a second voltage from the second PGA, wherein the first voltage is determined from a PGA coupled to a first secondary winding, and wherein the second voltage is determined from a second PGA coupled to a second secondary winding, iteratively performing: analyzing the first voltage to determine a gain correction is needed for a first gain for the first PGA, the gain correction comprising change to the first gain, and analyzing the second voltage to determine a gain correction is needed for a second gain for the second PGA, the gain correction comprising change to the second gain, based on determining a gain correction is not needed for the first gain and the second gain, calculating a position based on the first voltage and the second voltage.

A method for calibrating a receiver of an isolator product includes adjusting a peaking frequency of a receiver signal path of a first integrated circuit die of the isolator product and a gain of the receiver signal path based on a predetermined peaking frequency, a predetermined gain, a first level of a diagnostic signal during a first interval, and a second level of the diagnostic signal during a second interval. The first interval and the second interval are non-overlapping intervals. The method may include receiving a calibration signal on a differential pair of nodes of the receiver signal path of the first integrated circuit die. The method may include generating a diagnostic signal corresponding to an average amplitude of a received version of the calibration signal.

An audio mixer includes a user interface, panners, a first adder, a localization device, a second adder, and an output circuit. The user interface supplies a first parameter and a second parameter for each channel based on a user operation. The first parameter indicates a position in a right-left direction. The second parameter specifies internalization or externalization. The panners respectively correspond to channels and, based on the first parameter, pan a sound signal corresponding to the each channel to generate first stereo signals. The first adder generates a second stereo signal by mixing first stereo signals respectively corresponding to externalization channels. The localization device generates two third stereo signals. The second adder generates a fourth stereo signal by mixing the two third stereo signals and first stereo signals respectively corresponding to internalization channels. The output circuit outputs the fourth stereo signal.

A phase optimizer optimizes, for each listening position in a listening environment, a phase shift for each frequency in a range of predetermined frequencies. The phase optimizer determines a resultant phase value for each possible phase shift value and stores the resultant phase values for each possible phase shift value in an array. The phase optimizer calculates mean and standard deviation for the resultant phases stored in the array. The mean and standard deviations stored in the array are compared and phase shift values that result in the resultant phase values having the smallest mean and standard deviations are selected and are stored in memory. The phase optimizer optimizes each frequency, within a predetermined range of frequencies, for all possible phase shift values within a predetermined range of phase shift values and generates a phase shift target curve generated to be output by the phase optimizer.

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.

Embodiments are described herein that provide a dedicated command device that is bonded to a zone player or zone to perform adjustments to the zone player or zone. In an example implementation, a command device receives an instruction to pair with a first playback device that is associated with a group of playback devices that includes the first playback device and at least one additional playback device. The group of playback devices is associated with at least one group variable controlling playback by the playback devices of the group. The command device receives an input to adjust a first group variable of the at least one group variable and transmits, via a wireless communications interface, a command that causes an adjustment of the first group variable for the group of playback devices.