Question: What is a key difference in the implementation of the noise estimator between the encoder and decoder in FD-CNG (Fullband-Codec for Enhanced Voice Services - Comfort Noise Generation)?
Option 1: The type of non-linear transform applied to input partition energies differs.
Option 2: The number of partitions used for noise estimation differs, but the same noise tracking algorithm is applied.
Option 3: The decoder does not utilize an inverse transform after noise tracking, unlike the encoder.
Option 4: The encoder and decoder use entirely different noise tracking algorithms.
Explanation: This correct answer highlights a nuanced understanding of FD-CNG's implementation details. The difference in the number of partitions between the encoder and decoder is crucial for their respective operations, yet they share the same foundational approach to noise estimation, including the application of a non-linear transform and an inverse transform for dynamic range recovery. This shared methodology ensures consistency while accommodating the distinct operational needs of each component.