Schematic diagram of the supervised learning approach for obtaining the inverse map of M.

The ILD signal is calculated for all directions (θ, φ)∈X fixing the ear motions. It is discretized at time intervals of 1 ms and passed to the input layer of the neural network. In the neural network, the ReLU activation function is used in hidden layers 1, 2, and 3, and the mean squared error is the error function in the output layer.