Best with headphones! Your mouse is the audio source. Press Space to change mode. I have found a way to play 3d stereo audio that nobody has ever done on Scratch! Mode 0 (already known on Scratch): This mode uses the audio pan block, volume and some math to change the volume of the left and right speaker separately. It does not sound good, but it gives you a sense of where the audio source is. Mode 1 (new): This mode uses the audio pitch block, volume, pan and a lot of math to create a small time difference for the left and right speaker. When audio comes from the right, it first reaches your right ear and then half a millisecond later your left ear. Depending on this time your brain calculates the angle from wich the sound came. The pitch block makes the sound faster, so it sounds higher. An increase of +10 makes the sound a halftone higher (and also a bit faster). The project calculates this pitch value depending on the time difference (maximum pitch is about 3). The project has two sprites, one left and one right. They both play the same sound, but with pan = -100 or +100. They change their pitch for one frame and then reset it. This means that one audio is ever so slightly behind the other one and this creates the 3d effect. There is also some math for the volume, but that is not so new or important. It just calculates the volume based on distance and angle. Mode 2: This is Mode 1 but with full volume. This is the actually new thing. It uses only pitch! This could also work with two normal speakers (left and right), but it is designed for headphones. For my Minecraft 3d Multiplayer!