Question: In EVS (Enhanced Voice Services) codec, UC mode, how is the noisiness parameter primarily utilized in the decoder to enhance audio quality?
Option 1: To amplify low-frequency components in active speech segments
Option 2: For an anti-swirling technique to improve background noise representation during inactive speech
Option 3: To adjust the gain of the excitation vector in stationary active segments
Option 4: To determine the optimal LP filter order for varying speech patterns
Explanation: The correct answer highlights the noisiness parameter's role in enhancing background noise during inactive speech via an anti-swirling technique, crucial for maintaining a natural audio environment in voice communications, especially in UC mode. The other options misrepresent the application context or technical purpose.