How to speak with microphone in nds simulator

First, double-click the speaker that controls the sound in the toolbar at the lower right corner of the computer-click Options Properties-turn off the microphone under playback and select the microphone under recording. That should be enough.

In addition, if your simulator is not $GBA, press F 1 1 to pop up the simulator setting window, set the sound output mode to digital stereo, and set the required sound sampling rate to high (44kHz) (the best).

PS There are two items in the picture you intercepted: "playing" and "recording". The microphone should be under "Recording". If not, it is a sound card driver problem. Try to upgrade it.