Adaptive digital noise canceller

A technology of noise cancellation and canceller, which can be used in sound-producing equipment, earphones to reduce environmental noise, instruments, etc., and can solve problems such as affecting noise.

Inactive Publication Date: 2013-01-02
ROBERT BOSCH GMBH
View PDF6 Cites 13 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are also secondar...

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Adaptive digital noise canceller
  • Adaptive digital noise canceller
  • Adaptive digital noise canceller

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0021] Before any embodiments of the invention are set forth in detail, it is to be understood that the invention is not limited in application to the details of construction and arrangement of components set forth in the following description or shown in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways.

[0022] Embodiments of the invention described herein relate to an adaptive feedforward noise cancellation system for headphones used in, for example, aircraft cockpits or other high noise environments. The system includes three or more reference microphones, a controller, and an error microphone. The controller includes an auxiliary path model module, an adaptive controller, and a canceller filter. For a noise cancellation system to function properly, the anti-noise signal must be generated in less time than it takes for sound (eg, a noise signal) to travel from at least one of the reference microphones to the...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

Systems and methods for adaptive feed-forward noise cancellation. The system includes a plurality of reference microphones, an error microphone, a secondary path module, an adaptation controller, and a canceller filter. A finite impulse response ("FIR") based plant model is converted to an infinite impulse response ("HR") based plant model using balanced model reduction. Due to the inherent instability of the adaptive HR filter, the Schur-Cohn stability test is applied to the denominator coefficients of the HR filter transfer function to determine the stability of the noise cancellation system. A secondary path of the noise cancellation system is identified in an on-line manner in the secondary path module. If the energy level of the communication signal (e.g., a music signal) is strong, secondary path identification is performed.; The adaptation controller controls the updating of the HR transfer function based on the stability determination and the secondary path. An anti-noise signal is then generated and added to the communication signal. The anti-noise signal is generated within approximately 60 or fewer micro-seconds.

Description

technical field [0001] The present invention relates to noise canceling headphones (eg, headphones, earbuds, etc.). Background technique [0002] Noise-cancelling headphones are used in high-noise environments, such as airplane cockpits or near loud machinery, and elsewhere. Various techniques have been developed to provide noise cancellation in headphones. For example, many conventional noise cancellers use analog noise cancellation and use feedback or feedforward control techniques. Feedback noise cancellation is often used in headphones with loud chambers. Feed-forward noise cancellation is commonly used in earbuds and on-ear headphones. [0003] Feedforward noise cancellers use the principle of superposition to cancel unwanted ambient noise signals reaching the wearer's ears. For example, a feed-forward noise canceller uses a canceller filter based on a plant model (eg, transfer function) of the earphone to generate an anti-noise signal. Specifically, the canceller ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G10K11/178
CPCG10K11/178G10K2210/3049G10K2210/3017G10K2210/1053G10K2210/30232G10K2210/1081G10K11/17881G10K11/17817G10K11/17885H04R1/1083G10K11/17827G10K11/17833G10K11/17854
Inventor L·泰夫拉普鲁马T·A·约瑟夫
Owner ROBERT BOSCH GMBH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap