Question: In EVS (Enhanced Voice Services) decoding, what is the primary purpose of applying an inverse operation after LP synthesis filtering during the reconstruction of the audio signal?
Option 1: To enhance the harmonic structure of the signal
Option 2: To increase the output sample rate
Option 3: To generate the high-band signal component
Option 4: To reverse pre-emphasis applied at the encoder (de-emphasis)
Explanation: De-emphasis is an essential step in the decoding process of audio signals, including EVS. It reverses the pre-emphasis that was applied at the encoding stage to boost high-frequency components. This step ensures that the reconstructed signal has a balanced frequency response, similar to the original input signal.