Evaluation of Speech Intelligibility for Feedback Adaptive Active Noise Cancellation Headset

In the noise environment of the modern society, everybody may be influenced by noise. Therefore, there have lots of workers must wearing the hearing protector to avoid the injury to its sense of hearing of various kinds of industrial noises in its environment. The conventional passive methods, such as ear muffs, are ineffective against low-frequency noise. To solve this problem, the present study developed a headset equipped with a digital signal processing system to implement feedback adaptive active noise cancellation (FbAANC) to reduce the low-frequency noise. The proposed FbAANC headset was effective against wideband industrial noise, with a maximal noise spectrum power reduction of 37.9 dB. The study also evaluates the effects of FbAANC headset on speech intelligibility on a disyllabic Mandarin word discrimination test (WDT) platform. Finally, the SNR below -10 dB, the mean WDT score with FbAANC headset was superior to without FbAANC headset 13 to 32% through 30 subjects of normal hearing threshold for evaluation. These results suggest that the FbAANC headset would be useful for hearing protection in workplaces with high levels industrial noise.