公开(公告)号：US3585311A

公开(公告)日：1971-06-15

申请号：US3585311D

申请日：1969-09-02

Applicant: BELL TELEPHONE LABOR INC

Inventor： BERKLEY DAVID A ,  MITCHELL OLGA M M

IPC: H04B3/21 ,  H04M9/08

CPC classification number: H04M9/087 ,  H04B3/21

Abstract: The effect of circuit echo and long-time room reverberation in telephonic links are reduced by contiguous band filtering of the signal followed by center clipping of the filter outputs. Distortion products of the clippers are removed in a second filtering stage. A two-thirds octave filter passband width is advantageous.

公开(公告)号：US3644674A

公开(公告)日：1972-02-22

申请号：US3644674D

申请日：1969-06-30

Applicant: BELL TELEPHONE LABOR INC

Inventor： MITCHELL OLGA M M ,  ROSS CAROLYN ,  WALLACE ROBERT L JR

IPC: G10K11/178 ,  H04M9/00 ,  H04R3/00 ,  H04B15/00

CPC classification number: H04R3/005 ,  G10K11/178 ,  G10K2210/108 ,  G10K2210/1082 ,  G10K2210/111 ,  G10K2210/3012 ,  G10K2210/3045 ,  H04M9/001

Abstract: Signals from a desired source, such as a person speaking, are enhanced relative to unwanted ambient sound by a speech processor that includes an array of microphones arranged at equal distances from the desired source. The unwanted sound, being ''''off-center, '''' arrives nonconcurrently at the individual microphones. The processor continuously arranges the instantaneous microphone outputs in order of their relative energy contained, and selects as its output some one of the microphone outputs that is intermediate in the instantaneous ranking.