Abstract: A portable audio system with an integral hearing test is disclosed. The device includes a plurality of filter circuits. A processor applies a respective audio frequency to each filter circuit in a test mode to determine a respective gain based on a user input and applies the respective gain to each filter circuit in a normal mode. A switch circuit selects an audio signal from a plurality of sources in the normal mode. An analog-to-digital converter converts the selected audio signal to a digital signal and applies the digital signal to the plurality of filter circuits. A sum circuit receives a digital output signal from each of the plurality of filter circuits and produces a combined signal. A digital-to-analog converter converts the combined signal to an analog output signal.

Abstract: A portable audio system with an integral hearing test is disclosed. The device includes a plurality of filter circuits. A processor applies a respective audio frequency to each filter circuit in a test mode to determine a respective gain based on a user input and applies the respective gain to each filter circuit in a normal mode. A switch circuit selects an audio signal from a plurality of sources in the normal mode. An analog-to-digital converter converts the selected audio signal to a digital signal and applies the digital signal to the plurality of filter circuits. A sum circuit receives a digital output signal from each of the plurality of filter circuits and produces a combined signal. A digital-to-analog converter converts the combined signal to an analog output signal.

Abstract: An audio circuit with an integral hearing test is disclosed. The circuit includes at least one variable gain amplifier (VGA) coupled to receive an audio signal and a plurality of filters. Each filter is coupled to the at least one VGA and configured to filter an output signal from the at least one VGA. A processor is coupled to the VGAs and configured to apply a selected frequency to the at least one VGA in a test mode and to control a gain of the at least one VGA in a normal mode.

Abstract: An audio circuit with an integral hearing test is disclosed. The circuit includes at least one variable gain amplifier (VGA) coupled to receive an audio signal and a plurality of filters. Each filter is coupled to the at least one VGA and configured to filter an output signal from the at least one VGA. A processor is coupled to the VGAs and configured to apply a selected frequency to the at least one VGA in a test mode and to control a gain of the at least one VGA in a normal mode.