| 摘要 |
A noise activity detector includes a circuit for calculating average energy in a critical bandwidth, a circuit for determining a threshold function, a circuit for generating a dynamic modification of the threshold function, a circuit for identifying frequency components of the signal having energy that is above threshold values determined by the threshold function, and to determine a first average energy value representing an average energy of the identified frequency components with energy above the threshold, a circuit for identifying frequency components of the signal having energy that is below threshold values determined by the threshold function, and to determine a second average energy value representing an average energy of the identified frequency components with energy below the threshold, a circuit for offsetting at least one of the first and second average energy values, a circuit for comparing the resultant average energy values with one another, and a circuit for indicating the presence of noise activity if the first average energy value is below the second average energy value.
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