| 摘要 |
An apparatus and method to characterize an input communication signal as being a voice, tone or noise signal is provided. The apparatus and method involve measuring variations of pitch over time from a sampled input signal. A minimum value of Average Magnitude Difference Function (AMDF) over a pitch range and an average variation value of the AMDF over sampled intervals are used to determine whether the signal is a voice signal, a tone or noise. Historical data of these values is maintained in a dual buffer arrangement and is used in the determination of signal type by detecting transitions. |
