Performance Evaluation of the Cepstral Method to Estimate the Stable Optimal Solution of Feedforward Occlusion Cancellation in the Presence of Noise

This work aims to evaluate the performance of the cepstral method to estimate, in the presence of noise, the stable optimal solution of feedforward occlusion cancellation. The estimation is performed using the feedback structure for occlusion cancellation in a calibration process that may occur before using the hearing aid or when the user finds it convenient. Real-world occlusion path, acoustic path, and speech signals were employed. Simulations showed that the efficiency of the method reduces when decreasing the signal-to-noise ratio (SNR) at the hearing aid external microfone. For an analysis window of 2 s, estimates with mean normalized misalignment (MIS) less than \(-6\) , \(-14\) and \(-22\)  dB are obtained for SNRs of 30, 40 and 50 dB, respectively. For a window of 4 s, mean MIS less than \(-16\) and \(-24\)  dB are achieved for SNRs of 40 and 50 dB, respectively. The results indicate that the calibration process needs to be carried out in an acoustically controlled environment to maximize the accuracy of the stable solution estimate.