Abstract: A portable electronic device includes an earphone jack capable of receiving different types of earphone plugs, a switch, a detecting terminal, and a controlling terminal. The switch is connected to the earphone jack, and capable of switching between a first state and a second state. The detecting terminal is connected to the earphone jack by the switch, and capable of detecting the type of the earphone plug received in the earphone jack. The detecting terminal is connected to the earphone jack by the switch, and capable of detecting the type of the earphone plug received in the earphone jack. The controlling terminal is connected to the switch, and switches the switch to either the first state or the second state according to the type of the earphone plug.

Abstract: A valve power amplifier stage for an audio amplifier, which amplifier stage has at least one thermionic valve and a polarization circuit for polarizing the anode, the cathode and the control grid of the thermionic valve so as to determine the maximum output power. The polarization circuit comprises an adjusting module for adjusting the feed voltage of the anode and the polarization voltage of the control grid so as to adjust the maximum output power of the thermionic valve, and a potentiometer coupled with the adjusting module for allowing a user to control the adjusting means so as to select the desired maximum output power from a plurality of predetermined output power values.

Abstract: A signal processing device comprising a signal processing unit for processing an electrical SPU-input signal comprising frequencies in the audible frequency range between a minimum frequency and a maximum frequency, and providing a processed SPU output signal. An FM to AM transformation unit transforms an FM2AM input signal originating from the SPU-input signal and comprising at least a part of the frequency range of the SPU-input signal from a frequency modulated signal to an amplitude modulated signal to provide an FM2AM output signal, which is used in the generation of the processed SPU output signal.

Abstract: Methods, systems and computer-readable medium reduce and/or eliminate errors in coding/decoding of streamed audio due to resetting of decoder state values based on playback buffer access. An inaudible compensation signal is included with the audio signal. The compensation signal is generated having a characteristic selected so that the encoded streamed audio signal substantially matches the reset state values at block boundaries. In an ADPCM example, the compensation signal is chosen such that the sum of the compensation signal and the original audio signal (=the compensated audio signal) has the characteristic that, at the block boundaries, the compensated audio signal matches the initial predictor value.

Abstract: A radio configured to dynamically control cancellation of undesired signals in an audio stream. The radio includes a noise cancellation processor configured to receive an audio stream from a user and to alter information in the audio stream by filtering out undesired signals in the audio stream. The radio also includes a receiving component configured to receive a data packet from a remote device, to retrieve configuration information from the data packet, and to dynamically apply the configuration information, while the radio is being used by a user, to settings associated with the noise cancellation processor. A dynamically enabled noise cancellation processor suppresses undesired signals associated with a subsequent incoming audio stream provided by the user and transmits at least one of an altered audio stream or an unaltered audio stream to the remote device.

Abstract: Where information is to be conveyed as acoustic waves, embodiments of the present invention provide a transmitter capable of causing acoustic waves that convey information to be not easily perceived by the human ear. A transmitter, being an apparatus that converts various types of encoded information into acoustic wave(s) in the audible spectrum and carries out transmission thereof, comprises microphone(s) that cause ambient sound(s) from location(s) at which acoustic wave(s) is/are transmitted to be input as ambient sound signal(s); peak frequency detector(s) that detect, within ambient sound signal(s), peak frequency or frequencies of major constituent(s) of ambient sound(s); carrier wave generator(s) that generate carrier waves at a plurality of frequencies that are natural number multiples of peak frequency or frequencies and that can be used to mask ambient sound(s); and modulator(s) that modulate a plurality of carrier waves with baseband signal(s).

Abstract: A system and method for generating a sound that simulates a fictitious sound perceived to emanate from a fictitious sound location is disclosed. In at least one aspect, the system includes a first surface serving to at least partially enclose a first region, a first speaker positioned on the first surface, a second region within the first region, and a sound reflecting boundary to enclose the first region. The system further includes a first fictitious source location within the first region, the location being outside of the second region, and a control device coupled at least indirectly within the first speaker. The control device generates control signals configured to cause the first speaker to generate sounds that in turn produce actual sounds that simulate fictitious sounds perceived to emanate from fictitious sound locations.

Abstract: A clear, high quality voice signal with a high signal-to-noise ratio is achieved by use of an adaptive noise reduction scheme with two microphones in close proximity. The method includes the use of two omini directional microphones in a highly directional mode, and then applying an adaptive noise cancellation algorithm to reduce the noise.

Abstract: Devices, apparatus, methods, circuits and processors are implemented for control of audio signals. Consistent with one such apparatus, a processor circuit is configured and arranged to determine, for a perceived loudness algorithm that outputs audio signal levels, a common point corresponding to a particular background noise level at which the levels of the audio signal levels are independent of a volume setting that corresponds to desired perceived loudness, and to determine an audio signal level from the perceived loudness algorithm in response to a background noise signal, a volume setting signal, and the common point. An audio signal level output circuit is configured and arranged to provide an audio signal at the determined audio signal level.

Abstract: Provided is method for automatic audio gain modulation and a related apparatus. In order to prevent the unstable signals as continuously increasing or decreasing the gain when the signals hover around an upper threshold, it's featured that the method is to predict the signal intensity as pre-adding a predict gain in a hold time before outputting signals. By determining whether the prediction exceeds a predetermined threshold or not, the suitable and adjustable gains can be obtained without exceeding the predetermined threshold. In the automatic gain control mechanism, it's to decrease the gain gradually as automatically entering an attack time, or to increase the gain gradually as performing a conventional auto-gain control procedure including entering a release time. The claimed method can modulate the gain automatically by predicting the gain, and confine the signals under a threshold. In addition to avoid sawtooth phenomena, the method can stabilize the signals.