Provided are, among other things, systems, methods and techniques for processing an audio signal to add virtual bass. In one representative embodiment, an apparatus includes: (a) an input line that inputs an original audio signal; (b) a bass extraction filter that extracts a bass portion of such original audio signal; (c) an estimator that estimates a fundamental frequency of a bass sound within such bass portion; (d) a frequency translator that shifts the bass portion by a positive frequency increment that is an integer multiple of the fundamental frequency estimated by the estimator, thereby providing a virtual bass signal; (f) an adder having (i) inputs coupled to the original audio signal and to the virtual bass signal and (ii) an output; and (g) an audio output device coupled to the output of the adder.

An audio signal processing method, device and storage medium, are provided. The method includes performing sub-band filtering on a to-be-processed audio signal to obtain a plurality of sub-band signals, wherein the number of the sub-band signals is determined according to a lowest frequency of a band-pass filter and a cut-off frequency of an audio apparatus, and the sub-band signals comprise sub-band band-pass signals; and obtaining a target audio signal according to each of the sub-band band-pass signals and a processing algorithm of virtual bass enhancement signal.

A circuit device (100) includes a PWM signal output circuit (110) that outputs a PWM signal (SPWM) to a sound outputter (10), and a processing circuit (120) that controls the PWM signal output circuit (110). The frequency band that the sound outputter (10) can output is denoted as an outputtable band, and the frequency band lower than a lower limit of the outputtable band is denoted as a non-output low frequency band. The PWM signal output circuit (110) outputs a PWM signal (SPWM) based on pseudo sound data in which overtones, of a plurality of overtones of a fundamental tone belonging to the non-output low frequency band, that belong to the outputtable band are used.

A system and method for enhancing the real and/or perceived bass band of an audio signal is disclosed. A computationally simple yet effective bass band enhancement system for use in consumer electronics applications is disclosed. An audio processing system including bass enhancement functionality for use in a mobile audio system is disclosed.

Apparatus for processing an audio signal including an audio processing device configured to process, evaluate and modify an audio signal.

Apparatus for processing an audio signal including an audio processing device configured to process, evaluate and modify an audio signal.

A system includes a circuitry that provides for psychoacoustic frequency range extension for a speaker. The circuitry generates quadrature components from an audio channel, and generates rotated spectral quadrature components by applying a forward transformation that rotates a spectrum of the quadrature components from a standard basis to a rotated basis. In the rotated basis, the circuitry isolates components of the rotated spectral quadrature components at target frequencies, and generates weighted phase-coherent harmonic spectral quadrature components by applying a scale-independent nonlinearity to the isolated components. The circuitry generates a harmonic spectral component by applying an inverse transformation that rotates a spectrum of the weighted phase-coherent harmonic spectral quadrature components from the rotated basis to the standard basis. The circuitry combines the harmonic spectral component with frequencies of the audio channel outside of the target frequencies to generate an output channel, and provides the output channel to the speaker.

A circuit device (100) includes a PWM signal output circuit (110) that outputs a PWM signal (SPWM) to a sound outputter (10), and a processing circuit (120) that controls the PWM signal output circuit (110). The frequency band that the sound outputter (10) can output is denoted as an outputtable band, and the frequency band lower than a lower limit of the outputtable band is denoted as a non-output low frequency band. The PWM signal output circuit (110) outputs a PWM signal (SPWM) based on pseudo sound data in which overtones, of a plurality of overtones of a fundamental tone belonging to the non-output low frequency band, that belong to the outputtable band are used.

A system includes a circuitry that provides for psychoacoustic frequency range extension for a speaker. The circuitry generates quadrature components from an audio channel, and generates rotated spectral quadrature components by applying a forward transformation that rotates a spectrum of the quadrature components from a standard basis to a rotated basis. In the rotated basis, the circuitry isolates components of the rotated spectral quadrature components at target frequencies, and generates weighted phase-coherent harmonic spectral quadrature components by applying a scale-independent nonlinearity to the isolated components. The circuitry generates a harmonic spectral component by applying an inverse transformation that rotates a spectrum of the weighted phase-coherent harmonic spectral quadrature components from the rotated basis to the standard basis. The circuitry combines the harmonic spectral component with frequencies of the audio channel outside of the target frequencies to generate an output channel, and provides the output channel to the speaker.

Provided are, among other things, systems, methods and techniques for processing an audio signal to add virtual bass. In one representative embodiment, an apparatus includes: (a) an input line that inputs an original audio signal; (b) a bass extraction filter that extracts a bass portion of such original audio signal; (c) an estimator that estimates a fundamental frequency of a bass sound within such bass portion; (d) a frequency translator that shifts the bass portion by a positive frequency increment that is an integer multiple of the fundamental frequency estimated by the estimator, thereby providing a virtual bass signal; (f) an adder having (i) inputs coupled to the original audio signal and to the virtual bass signal and (ii) an output; and (g) an audio output device coupled to the output of the adder.