Patent ID: 8873763

Claim:
A device for processing an input sound signal to enhance aural perception of low-frequency signal components in the input sound signal, whereby an output sound signal of the device incorporates residue harmonics of the low-frequency signal components, and the low-frequency signal components are absent from the output sound signal but a human listener who listens to the output sound signal still psychologically perceive the presence of such components due to the presence of the residue harmonics, the device comprising: a low pass filter for extracting the low-frequency signal components of the input sound signal, the low-frequency signal components comprising signal components substantially from zero Hz to a Half Loudness Frequency, the low pass filter generating a low-pass signal; a compressive amplitude function processor for generating a harmonics-containing signal as output based on the low-pass signal as input, an input-output relationship of the compressive amplitude function processor being a nonlinear function emulating the middle-ear response of a human being, whereby the residue harmonics of the low-frequency signal components are generated and form part of the harmonics-containing signal; a gain block for providing gain to the harmonics-containing signal, the gain block producing a scaled harmonics-containing signal, the gain being selected such that the signal strength of the scaled harmonics-containing signal is in the same range as that of the initial low-pass signal; an adder for adding the input sound signal and the scaled harmonics-containing signal, generating an adder output; and a high pass filter for generating the output sound signal by extracting the frequency components of the adder output substantially above the Half Loudness Frequency, thereby removing the low frequency signal components in the output sound signal while still including the residue harmonics.