Question: Under which condition(s) are the gain shape parameters smoothed for a current frame in EVS (Enhanced Voice Services) codec, considering the pitch gain and coding types of both the current and previous frames?
Option 1: When the coding type of both frames is the same, or when there's a specific swap between GENERIC and VOICED types, and the pitch gain exceeds 70.
Option 2: Only when both the current and previous frames are classified as VOICED, regardless of the pitch gain value.
Option 3: Whenever the coding type changes from GENERIC to VOICED or vice versa, without considering the pitch gain threshold.
Option 4: If the pitch gain of the current frame is below 70, for all combinations of GENERIC and VOICED coding types between frames.
Explanation: The correct answer accurately reflects the conditions under which the gain shape parameters are smoothed: (i) when both frames have identical coding types, or (ii) in specific transitions between GENERIC and VOICED types, with the pitch gain of the current frame being greater than 70, ensuring a balanced approach to maintaining audio quality.