Abstract: The present invention relates to electric audio devices and to communication devices. It also relates to the protection and increased performance of audio devices and electro acoustic 5 transducers like loudspeakers and headphones in portable devices and fixed installed equipment in entertainment products. The present invention provides a method for operating a dynamic range control with an adaptive threshold. A dynamic range control comprises at least an audio signal input, an audio signal output and a power or volume control. The method comprises receiving a number of thresholds comprising at least a maximum power level for short time interval operation and a maximum power level for long time operation of an electro acoustic transducer. The method further comprises continuously detecting the power of the audio input signal.

Abstract: The present invention relates to a method and mobile electronic device for enabling a user to simultaneously monitor two different audio signals. The mobile electronic device has a first and a second audio component for providing a first and a second audio signal, and an audio output for outputting an audio signal. The audio output is connected to said first and second audio components. The mobile device further comprises a mixer, connected between the first and second audio component and the audio output for mixing the first and second continuous audio signals to generate a mixed signal to be supplied to the audio output. The mixed signal comprises components of both audio signals so that a user can simultaneously monitor two different audio signals. An application is to enable a user to monitor an audio recording while using a mobile telephone.

Abstract: The present invention discloses a mobile electronic device, having a radio receiver (28), an amplifier (24) and an audio connector (20) for connecting to a headphone (2). Said audio connector (2) comprises at least one first contact and at least one second contact, wherein said first contact is connected to ground and to said radio receiver (28), and said second contact is connected to said amplifier (24). The electronic device is characterized by a band-pass filter component (26) interconnected between said first contact and said radio receiver (28) so that only a predefined frequency range can pass to the radio receiver, preventing cross talk interference from transmitters operated in proximity.

Abstract: The invention concerns an amplifier circuit for an IC whereby continuous symmetrical signal routing can be provided from the inputs to the outputs, without branches and crossovers and at low cost. The IC can be used as amplifier, buffer, line driver and line receiver with a minimum of external wiring. Two operational amplifiers (OA1) and (OA2) are each connected as non-inverting amplifiers and include integrated feedback impedances (RF1, RF2), a joint resistor (R 3) for adjusting the differential amplification, and a subtraction stage. According to the invention two complementary, parallel-connected differential amplifiers (DIF 1 and DIF 2) form the subtraction stage, each of which has its own pair of signal outputs (O 11/O 12 or O 21/O 22) for one differential signal in each case. Each of the signal outputs (O 11/O 12 or O 21/O 22) leads to its own driver (DV 11, DV 12, DV 21 and DV 22), which are interconnected so as to create a push-pull output stage in a bridge circuit.