| Patent application number | Description | Published |
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| 20100020979 | ADAPTIVE LONG-TERM PREDICTION FILTER FOR ADAPTIVE WHITENING - The invention relates to a hearing instrument for processing an input sound to an output sound according to a user's needs. The invention further relates to a method of estimating acoustic feedback in a hearing instrument. The object of the present invention is to reduce the impact of tonal components in the target input signal on the quality of the estimate of acoustic feedback. The problem is solved in that hearing instrument comprises an input transducer for converting an input sound to an electric input signal and an output transducer for converting a processed electric output signal to an output sound, a forward path being defined between the input transducer and the output transducer and comprising a signal processing unit defining an input side and an output side of the forward path, a feedback loop from the output side to the input side comprising a feedback cancellation system for estimating the effect of acoustic feedback from the output transducer to the input transducer, the feedback cancellation system comprising a feedback path estimation unit receiving first and second estimation input signals from the input and output side of the forward path, respectively, wherein the first and second estimation input signal paths comprise first and second long term prediction filters P(z) each having an input and an output, the feedback cancellation system being adapted to provide that the variable parameters of at least one of the long term prediction filters are estimated based on the input signal to the filter in question. Embodiments of the invention have the advantage of leading to better feedback cancellation, even for tonal input signals. The invention may e.g. be used for the hearing instruments or headsets. | 01-28-2010 |
| 20100020981 | SPECTRAL CONTENT MODIFICATION FOR ROBUST FEEDBACK CHANNEL ESTIMATION - The invention relates to a listening device for processing an input sound to an output sound according to a user's needs. The invention further relates to a method of reducing acoustic feedback in a listening device and to the use of a listening device. The object of the present invention is to provide an alternative scheme for feedback estimation in a listening device. The problem is solved in that the listening device comprises an input transducer for converting an input sound to an electric input signal, and an output transducer for converting a processed electric output signal to an output sound, a forward path being defined between the input transducer and the output transducer and comprising a signal processing unit adapted for processing an SPU-input signal originating from the electric input signal in a time-frequency representation comprising successive time frames each comprising a frequency spectrum of the signal in the time frame in question, the signal processing unit defining an input side and an output side of the forward path and comprising a spectral content modification unit adapted for modifying values of the signal of one or more regions of the frequency spectrum of a given time frame to provide that the modified values are less correlated to the corresponding time-frequency regions of the input signal than the unmodified output signal thereby providing an improved processed output signal, and a feedback loop from the output side to the input side comprising a feedback path estimation unit for estimating the effect of acoustic feedback from the output transducer to the input transducer, wherein the feedback path estimation unit is adapted to use the improved processed output signal in the estimation. This has the advantage of providing a better accuracy vs. tracking speed trade-off of the feedback path estimate. The invention may e.g. be used for listening devices prone to acoustic feedback, e.g. hearing aids, headsets or active earplugs. | 01-28-2010 |
| 20100020995 | SYSTEM FOR REDUCING ACOUSTIC FEEDBACK IN HEARING AIDS USING INTER-AURAL SIGNAL TRANSMISSION, METHOD AND USE - The invention relates to a hearing aid system comprising first and second spatially separated hearing instruments, the system being adapted for processing input sounds to output sounds according to a user's needs. The invention further relates to a method and use. The object of the present invention is to provide an alternative scheme for reducing the effect of acoustic feedback in a hearing aid system. The problem is solved in that the hearing instruments comprises, respectively, first and second input transducers for converting a first input sound to first and second electric input signal, and first and second output transducers for converting first and second processed electric output signal to first and second output sounds, wherein the system is adapted to provide that a first Tx-signal originating from the first electric input signal of the first hearing instrument is transmitted to the second hearing instrument and used in the formation of the second processed electric output signal, and that a second Tx-signal originating from the second electric input signal of the second hearing instrument is transmitted to the first hearing instrument and used in the formation of the first processed electric output signal. This has the advantage of providing a scheme for reducing or effectively eliminating acoustic feedback in a pair of hearing instruments. The invention may e.g. be used in listening devices, e.g. hearing aids, head sets, or active ear plugs. | 01-28-2010 |
| 20100020996 | CODEBOOK BASED FEEDBACK PATH ESTIMATION - The invention relates to a hearing instrument for processing an input sound to an output sound according to a user's needs. The invention further relates to a method of operating a hearing instrument and to use of a hearing instrument. The object of the present invention is to provide an alternative scheme for handling acoustic feedback in a hearing instrument. The problem is solved in that an input transducer for converting an input sound to an electric input signal and an output transducer for converting a processed electric output signal to an output sound, a forward path being defined between the input transducer and the output transducer, a feedback cancellation system for estimating the effect of acoustic feedback from the output transducer to the input transducer, the feedback cancellation system comprising a variable pre-estimated filter and a memory wherein a number of predetermined feedback channel impulse responses corresponding to a number of acoustic environments where substantial feedback is experienced are stored, and wherein the hearing instrument comprises a monitoring unit that—based on the current acoustic environment—is adapted to choose the currently most appropriate impulse response of the variable pre-estimated filter among the stored impulse responses. This has the advantage of providing a scheme for handling acoustic feedback that can adapt relatively fast to changing acoustic environments. The invention may e.g. be used in listening devices, such as hearing aids, head sets or active ear plugs, wherein customized feedback compensation is an issue. | 01-28-2010 |
| 20100067710 | NOISE SPECTRUM TRACKING IN NOISY ACOUSTICAL SIGNALS - The invention relates to a method of estimating noise power spectral density PSD in an input sound signal comprising a noise signal part and a target signal part. The invention further relates to a system to its use. The object of the present invention is to provide a scheme for estimating the noise PSD in an acoustic signal consisting of a target signal contaminated by acoustic noise. The problem is solved by a method comprising the steps of d) providing a digitized electrical input signal to a control path and performing; d1) storing a number of time frames of the input signal each comprising a predefined number N2 of digital time samples x | 03-18-2010 |
| 20110150257 | ADAPTIVE FEEDBACK CANCELLATION BASED ON INSERTED AND/OR INTRINSIC CHARACTERISTICS AND MATCHED RETRIEVAL - The invention relates to an audio processing system for processing an input sound to an output sound. The invention further relates to a method of estimating a feedback transfer function in an audio processing system. The object of the present invention is to provide an alternative scheme for minimizing feedback in audio processing systems. The problem is solved in that the audio processing system comprises an input transducer for converting an input sound to an electric input signal and defining an input side, an output transducer for converting a processed electric output signal to an output sound and defining an output side, a forward path being defined between the input transducer and the output transducer, and comprising a signal processing unit adapted for processing an SPU-input signal originating from the electric input signal and to provide a processed SPU-output signal, and an electric feedback loop from the output side to the input side comprising a feedback path estimation unit for estimating an acoustic feedback transfer function from the output transducer to the input transducer, and a enhancement unit for estimating noise-like signal components in the electric signal of the forward path and providing a noise signal estimate output, wherein the feedback path estimation unit is adapted to use the noise signal estimate output in the estimation of the acoustic feedback transfer function. This has the advantage of providing an adaptive feedback cancellation system which is robust in situations with a high degree of correlation between the output signal and the input signal of an audio processing system, e.g. a listening device. The invention may e.g. be used in public address systems, entertainment systems, hearing aids, head sets, mobile phones, wearable/portable communication devices, etc. | 06-23-2011 |
| 20110224976 | SPEECH INTELLIGIBILITY PREDICTOR AND APPLICATIONS THEREOF - The application relates to a method of providing a speech intelligibility predictor value for estimating an average listener's ability to understand of a target speech signal when said target speech signal is subject to a processing algorithm and/or is received in a noisy environment. The application further relates to a method of improving a listener's understanding of a target speech signal in a noisy environment and to corresponding device units. The object of the present application is to provide an alternative objective intelligibility measure, e.g. a measure that is suitable for use in a time-frequency environment. The invention may e.g. be used in audio processing systems, e.g. listening systems, e.g. hearing aid systems. | 09-15-2011 |
