The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 03, 2012
Filed:
Apr. 29, 2009
Julien DE Muynke, Paris, FR;
Benoit Pochon, Paris, FR;
Guillaume Pinto, Paris, FR;
Parrot, Paris, FR;
Abstract
The method comprises the steps of: filtering the audio signal by means of a lowpass filter () with a cutoff frequency substantially equal to said cutoff frequency (F) of the sound playback device; determining a fundamental frequency for reconstituting from the lowpass filtered audio signal; and generating a harmonic signal (S) associated with said fundamental frequency to be reconstituted. It also comprises the steps of: detecting a time envelope (env(t)) of the lowpass filtered audio signal; adapting the dynamic range of said time envelope (env(t)) as a function of the frequency band under consideration; and reinjecting said harmonic signal in phase into said audio signal by addition after multiplying said harmonic signal (S) with the adapted time envelope (env(t)). The adaptation is performed by compression/expansion of the time envelope with feedback loop control that is adjusted automatically on the value of the envelope as a function of the mean energy of the input signal to a value that maximizes said energy within a defined limit.