GRNN 1 General regression neural network Lower frequencies 1 MFCC feature 1 Machine learning 1 Machine-learning 1 Mel frequency cepstrum coefficients 1 Mel-frequency cepstrum coefficient feature 1 Neural networks 1 Performance 1 Regression neural networks 1 Seal call recognition 1 Signal to noise ratio 1 Spread factors 1 Underwater acoustic signal 1 Underwater acoustics 1