puissance vocale

CONT: puissance vocale moyenne. Valeur moyenne, pendant un intervalle de temps donné, des puissances vocales instantanées. [Justification reproduite avec l'autorisation de l'AFNOR.]
OBS: puissance vocale instantanée. Valeur, à un instant considéré, de la puissance acoustique émise par la bouche. [Justification reproduite avec l'autorisation de l'AFNOR]

CONT: Speech Detection. If the Voice Activity Detector (VAD) option is active, a speech detector is used to identify periods of silence or idle VF channels to provide further compression in addition to ADPCM. This function is performed by the CDP card. The PCM signal is first passed through a high-pass filter to remove DC bias and 50/60 Hz. components that might disturb the speech or modem detectors. The energy of each sample is measured, and the average speech power is calculated. If the power is greater than -31 dBmO (dBmO equals a digital milliwatt), the signal is recognized as speech. This is a simplification of the VAD function.