EP 0852052 B1 20010613 - SYSTEM FOR ADAPTIVELY FILTERING AUDIO SIGNALS TO ENHANCE SPEECH INTELLIGIBILITY IN NOISY ENVIRONMENTAL CONDITIONS
Title (en)
SYSTEM FOR ADAPTIVELY FILTERING AUDIO SIGNALS TO ENHANCE SPEECH INTELLIGIBILITY IN NOISY ENVIRONMENTAL CONDITIONS
Title (de)
SYSTEM ZUR ADAPTIVEN FILTERUNG VON TONSIGNALEN ZUR VERBESSERUNG DER SPRACHVERSTÄNDLICHKEIT BEI UMGEBUNGSGERÄUSCHEN
Title (fr)
SYSTEME DE FILTRAGE ADAPTATIF DE SIGNAUX AUDIO DESTINE A AMELIORER L'INTELLIGIBILITE DE LA PAROLE DANS DES ENVIRONNEMENTS BRUYANTS
Publication
Application
Priority
- US 9614665 W 19960913
- US 52800595 A 19950914
Abstract (en)
[origin: WO9710586A1] A method and system are provided for adaptively reducing noise in frames of digitized audio signals that include both speech and background noise. Frames of digitized audio signals are passed through an adjustable, high-pass filter circuit to filter a portion of background noise located in a low frequency range of the digitized signal. The filter circuit is adjusted by a filter control circuit adapted for a current frame to exhibit a selected frequency response curve. The filter control circuit includes a speech detector for detecting the presence or absence of speech in the frames of digitized audio signals. The filter circuit is adjusted when no speech is detected in the current frame. In a first preferred embodiment, the filter control circuit controls the filter circuit by calculating a noise estimate corresponding to the background noise, and adjusting the filter circuit based on the noise estimate. As the noise estimates increase, the filter circuit is adjusted to extract increasing amounts of energy falling in low frequency ranges of speech. In a second preferred embodiment, the filter circuit is adjusted as a function of a noise profile estimate. A noise profile estimate for a current frame is determined as a function of speech detection and is compared to a reference noise profile. Based on this comparison, the filter circuit is adaptively adjusted.
IPC 1-7
IPC 8 full level
G10L 15/20 (2006.01); G10L 21/0208 (2013.01); G10L 21/0216 (2013.01); G10L 21/0232 (2013.01); G10L 25/78 (2013.01)
CPC (source: EP KR)
G10L 21/0208 (2013.01 - EP KR); G10L 21/0232 (2013.01 - EP); G10L 2021/02168 (2013.01 - EP); G10L 2025/786 (2013.01 - EP)
Designated contracting state (EPC)
BE DE DK ES FI FR GB GR IT NL PT SE
DOCDB simple family (publication)
WO 9710586 A1 19970320; AU 7078496 A 19970401; AU 724111 B2 20000914; BR 9610290 A 19990316; CA 2231107 A1 19970320; CN 1121684 C 20030917; CN 1201547 A 19981209; DE 69613380 D1 20010719; EE 03456 B1 20010615; EE 9800068 A 19980817; EP 0852052 A1 19980708; EP 0852052 B1 20010613; JP H11514453 A 19991207; KR 100423029 B1 20040701; KR 19990044659 A 19990625; MX 9801857 A 19981129; NO 981074 D0 19980311; NO 981074 L 19980513; PL 185513 B1 20030530; PL 325532 A1 19980803; RU 2163032 C2 20010210; TR 199800475 T1 19980622
DOCDB simple family (application)
US 9614665 W 19960913; AU 7078496 A 19960913; BR 9610290 A 19960913; CA 2231107 A 19960913; CN 96198008 A 19960913; DE 69613380 T 19960913; EE 9800068 A 19960913; EP 96931552 A 19960913; JP 51211297 A 19960913; KR 19980701913 A 19980313; MX 9801857 A 19980309; NO 981074 A 19980311; PL 32553296 A 19960913; RU 98107313 A 19960913; TR 9800475 T 19960913