Question: In the context of EVS (Enhanced Voice Services) codec, specifically within the tilt compensation filter of the short-term post-filter, how is the tilt factor value determined for calculation purposes?
Option 1: Based on a fixed value of 0.5, regardless of the sign of the first reflection coefficient.
Option 2: Dynamically calculated using a complex algorithm involving multiple reflection coefficients.
Option 3: Using two distinct values (0.9 and 0.2) dependent on whether the first reflection coefficient is negative or positive, respectively.
Option 4: Derived from an average of all reflection coefficients in the filter.
Explanation: The correct approach for determining the tilt factor value in EVS codec's tilt compensation filter involves adapting to the sign of the first reflection coefficient. This dynamic adjustment (using 0.9 for negative and 0.2 for positive coefficients) ensures an optimal compensation for the signal's tilt, reflecting a nuanced understanding of audio processing in telecom networks.