Question: What is a key reason for the streamlined inclusion of AMR-WB interoperable modes in the EVS codec?
Option 1: The EVS codec's core operates exclusively at a 12.8 kHz internal sampling rate.
Option 2: The ITU-T G.722.2 standard mandated interoperability with AMR-WB for all new codecs.
Option 3: Similarities exist between the EVS codec's core ACELP coder and AMR-WB, notably in internal sampling rate, pre-emphasis, and perceptual weighting.
Option 4: The EVS codec's primary design goal was backward compatibility with all existing voice codecs.
Explanation: The correct answer highlights the technical similarity between the EVS codec's core ACELP coder and AMR-WB, specifically in aspects like internal sampling rate, pre-emphasis, and perceptual weighting. These similarities facilitated the streamlined inclusion of interoperable modes, ensuring seamless communication between devices using either codec without significant additional complexity.