Title:
雑音挿入装置
Document Type and Number:
Japanese Patent JP4047475
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a noise inserting device for improving hearing characteristics in the case of cell-assembling only a sounded block (packetizing), transmitting it to the side of reception and inserting a pseudo noise into a soundless block. SOLUTION: A reproduced voice in the part of hang-over time is stored in a memory 20, the spectrum of a background noise just before the soundless block is analyzed by a spectrum analysis circuit 21, and the noise of the most similar spectrum is selected from a generation noise switcher 22 and inserted to the soundless block by a swicher 14. Namely, the spectrum structure of the background noise is analyzed by using fast Fourier transformation(FFT) and cepstrum analysis, etc., while using the data of a part corresponding to a final sounded cell at the time of long hang-over and on the basis of this analyzed result, the spectrum characteristics of a source sound generator are close to the spectrum of noise source. Thus, the noise close to the real background noise can be generated, the hearing characteristics are improved and transmission efficiency can be kept high.
Inventors:
Tomoko Takemitsu
Application Number:
JP3744399A
Publication Date:
February 13, 2008
Filing Date:
February 16, 1999
Export Citation:
Assignee:
nec Engineering Co., Ltd.
International Classes:
H04L12/56; G10L19/00; G10L19/012; G10L25/78; H04L12/28
Domestic Patent References:
| JP5083285A | ||||
| JP10039898A | ||||
| JP7050631A | ||||
| JP4362830A | ||||
| JP5049054A | ||||
| JP8314497A | ||||
| JP1183233A |
Attorney, Agent or Firm:
Masahiro Fukuyama