Interaural Level Difference (ILD)

Interaural Level Difference (ILD) is a cue our brain uses to locate the direction of a sound source. It refers to the difference in loudness or intensity of a sound arriving at each ear due to the head blocking some sound waves. When a sound comes from one side, it’s perceived as louder in the nearer ear and quieter in the farther ear. The brain compares these differences to determine where the sound originated, especially for high-frequency noises where the head creates a noticeable level disparity. ILD helps us identify the spatial position of sounds in our environment.