Active noise cancelation with controllable levels
AssigneeAvnera Corporation
InventorsAmit Kumar, Eric Sorensen
Life of this patent
Estimating the term…
Abstract
A system including an automatic noise canceling (ANC) headphone and a processor. The ANC headphone has a microphone configured to generate a microphone signal and at least two non-zero ANC gain levels. The processor is configured to receive the microphone signal, determine a characteristic of the microphone signal, and identify a revised ANC level from the ANC gain levels based on a comparison of the characteristic to at least one threshold. Methods are also disclosed.
Claims20
A noise reduction system comprising:
- an automatic noise canceling headphone having an automatic noise canceling feedforward microphone configured to generate a feedforward microphone signal, the automatic noise canceling headphone further having automatic noise canceling gain levels including at least two non-zero automatic noise canceling gain levels;
- and
- a processor configured to receive the feedforward microphone signal, determine a power value of a first frequency range of the feedforward microphone signal, determine a power value of a second frequency range of the feedforward microphone signal, and select one of the at least two non-zero automatic noise canceling gain levels based on the determined power values.
A method of reducing automatic noise canceling hiss in a headphone having an active noise cancellation system, the method comprising:
- generating a feedforward microphone signal from an automatic noise canceling feedforward microphone;
- determining a power value of a first frequency range of the feedforward microphone signal;
- determining a power value of a second frequency range of the feedforward microphone signal;
- and
- selecting one of at least two non-zero automatic noise canceling gain levels of the headphone based on the determined power values.
An automatic noise canceling level controller, comprising:
- a first bandpass filter configured to filter a feedforward microphone signal in a first frequency range;
- a second bandpass filter configured to filter the feedforward microphone signal in a second frequency range;
- a first estimator configured to determine a first power value of the first frequency range;
- a second estimator configured to determine a second power value of the second frequency range;
- and
- a threshold comparator configured to select one of at least two non-zero automatic noise canceling gain levels of a headphone based on the first power value and the second power value.
Dependencies are inferred from the claim text.