An amplifier stage uses a loaded transistor amplifier circuit including a load that causes greater second order harmonic distortion energy than third order harmonic distortion energy to be produced in said loaded transistor amplifier circuit for amplifying a source audio signal to produce an audio output signal. The spectrum of the fundamental orders of harmonic distortion is adjusted to improve perceived sound quality or listening enjoyment.

An amplifier stage uses a loaded transistor amplifier circuit including a load that causes greater second order harmonic distortion energy than third order harmonic distortion energy to be produced in said loaded transistor amplifier circuit for amplifying a source audio signal to produce an audio output signal. The spectrum of the fundamental orders of harmonic distortion is adjusted to improve perceived sound quality or listening enjoyment.

An apparatus for generating a presentation from content having original audio and video components is described wherein an environment detector is configured to output an environment-type signal indicating a detected particular environment. An acoustics memory is configured to output selected acoustic characteristics indicative of the environment identified by the environment-type signal. An audio processor receives the audio components and the acoustic characteristics and operates to modify the original audio components to produce modified audio components based on the selected acoustic characteristics. The presentation including the modified audio components is output.

A computer apparatus and computer-implemented apparatus for logging audio to an audio logger. Audio is transmitted from a source communication device. At least one receiving communication device receives the audio. The audio is logged to an audio logger, for example by the source communication device and the receiving communication device. A hash of the audio is computed and the hash of the audio and communication parameters related to the audio are stored in a blockchain.

Improved techniques for presenting sound effects at a portable media device are disclosed. The sound effects can be output as audio sounds to an internal speaker, an external speaker, or both. In addition, the audio sounds for the sound effects can be output together with other audio sounds pertaining to media assets (e.g., audio tracks being played). In one embodiment, the sound effects can serve to provide auditory feedback to a user of the portable media device. A user interface can facilitate a user's selection of sound effect usages, types or characteristics.

A computer apparatus and computer-implemented apparatus for logging audio to an audio logger. Audio is transmitted from a source communication device. At least one receiving communication device receives the audio. The audio is logged to an audio logger, for example by the source communication device and the receiving communication device. A hash of the audio is computed and the hash of the audio and communication parameters related to the audio are stored in a blockchain.

An amplifier stage uses a loaded transistor amplifier circuit including a load that causes greater second order harmonic distortion energy than third order harmonic distortion energy to be produced in said loaded transistor amplifier circuit for amplifying a source audio signal to produce an audio output signal. The spectrum of the fundamental orders of harmonic distortion is adjusted to improve perceived sound quality or listening enjoyment.

An audio appliance includes an oscillatable diaphragm, a first heat-dissipation unit, a second heat-dissipation unit, and a control unit. The first heat-dissipation unit dissipates heat at a first rate and the second heat-dissipation unit dissipates heat at a second rate. The control unit can receive an indication of a temperature of the first heat-dissipation unit and an indication of a temperature of the second heat-dissipation unit. The control unit provides oscillation control of the oscillatable diaphragm to maintain the temperature of the first heat-dissipation unit below a first threshold and/or to maintain the temperature of the second heat-dissipation unit below a second threshold. The control unit can provide the oscillation control responsive to each of the indication of the temperature of the first heat-dissipation unit and the indication of the temperature of the second heat-dissipation unit exceeding a respective threshold.

An apparatus for generating a presentation from content having original audio and video components is described wherein an environment detector is configured to output an environment-type signal indicating a detected particular environment. An acoustics memory is configured to output selected acoustic characteristics indicative of the environment identified by the environment-type signal. An audio processor receives the audio components and the acoustic characteristics and operates to modify the original audio components to produce modified audio components based on the selected acoustic characteristics. The presentation including the modified audio components is output.

Methods, systems and computer readable media for altering an audio output are provided. In some embodiments, the system may change the original frequency content of an audio data file to a second frequency content so that a recorded audio track will sound as if a different person had recorded it when it is played back. In other embodiments, the system may receive an audio data file and a voice signature, and it may apply the voice signature to the audio data file to alter the audio output of the audio data file. In that instance, the audio data file may be a textual representation of a recorded audio data file.