  Convolutional neural networks are sensitive to unknown noisy condition in the
test phase and so their performance degrades for the noisy data classification
task including noisy speech recognition. In this research, a new convolutional
neural network (CNN) model with data uncertainty handling; referred as NCNN
(Neutrosophic Convolutional Neural Network); is proposed for classification
task. Here, speech signals are used as input data and their noise is modeled as
uncertainty. In this task, using speech spectrogram, a definition of
uncertainty is proposed in neutrosophic (NS) domain. Uncertainty is computed
for each Time-frequency point of speech spectrogram as like a pixel. Therefore,
uncertainty matrix with the same size of spectrogram is created in NS domain.
In the next step, a two parallel paths CNN classification model is proposed.
Speech spectrogram is used as input of the first path and uncertainty matrix
for the second path. The outputs of two paths are combined to compute the final
output of the classifier. To show the effectiveness of the proposed method, it
has been compared with conventional CNN on the isolated words of Aurora2
dataset. The proposed method achieves the average accuracy of 85.96 in noisy
train data. It is more robust against Car, Airport and Subway noises with
accuracies 90, 88 and 81 in test sets A, B and C, respectively. Results show
that the proposed method outperforms conventional CNN with the improvement of
6, 5 and 2 percentage in test set A, test set B and test sets C, respectively.
It means that the proposed method is more robust against noisy data and handle
these data effectively.
