To enhance speech recognition, as well as Mandarin tone recognition in noice, we proposed a speech coding strategy called zero-crossing of fine structure in low frequency (LFFS) for cochlear implant based on low frequency non-uniform sampling (LFFS for short). In the range of frequency perceived boundary of human ear, we used zero-crossing time of the fine structure to generate the stimulus pulse sequences based on the frequency selection rule. Acoustic simulation results showed that although on quiet background the performance of LFFS was similar to continuous interleaved sampling (CIS), on the noise background the performance of LFFS in Chinese tones, words and sentences were significantly better than CIS. In addition to this, we also got better Mandarin recognition factors distribution by using the improved index distribution model. LFFS contains more tonal information which was able to effectively improve Mandarin recognition of the cochlear implant.
Acoustics ; Cochlear Implants ; Equipment Design ; Humans ; Language ; Noise ; Recognition (Psychology) ; Speech Perception

Objective:To investigate the trend of postoperative cavity status in patients with eosinophilic chronic sinusitis with nasal polyps (eCRSwNP) who underwent total nasalization surgery and partial reboot surgery. And to discuss the relationship between tissue eosinophil counts and status of postoperative cavity.Methods:Patients with eCRSwNP in four tertiary medical centers (Longgang ENT Hospital, Xiamen Humanity Hospital, Guangdong Clifford Hospital and the First Affiliated Hospital of Sun Yat-Sen University) from March 2018 to October 2021 were divided into 2 groups. The group without previous surgery history was performed for the nasalization surgery, and another group with previous surgery history underwent the part-reboot surgery. The follow-up time after operation was defined as the following 5 stages: 6, 12, 20-24, 36 and more than 42 months. According to FESS-95 Guangzhou standard, status of sinus cavity was assessed and classified into 3 categories: good, better and bad. The association between the sinus cavity status and tissue eosinophil counts in the above 5 stages was analyzed by one-way ANOVA, and P<0.05 was considered statistically significant. Results:A total of 72 eCRSwNP patients finished the follow-up in this study. There were 47 males and 25 females in these patients, aged from 11 to 67 years. A total of 50 cases underwent nasalization surgery and 22 cases underwent partial reboot surgery. With the follow-up time from 6 to 48 months, there were 72 cases (100.0%) who completed 6 months and 12 months follow up, 46 cases (63.9%) for 20-24 months, 36 cases (50.0%) for 32-36 months and 16 cases (22.2%) with the follow-up time more than 42 months. No matter what kind of surgery, there was no "bad" situation of the surgical cavity status 6 months after the operation, and the differentiation gradually occurred more than 12 months after the surgery. Moreover, the rates of "good" cavity status for the 5 stages in the group of nasalization surgery were 78.0%, 66.0%, 56.7%, 47.6% and 42.9%, and were 63.6%, 45.5%, 25.0%, 20.0% and 11.1% in the partial reboot surgery group, respectively, suggesting that the status of nasal cavity in nasalization surgery group was always better than that in partial reboot surgery group in every period. In addition, the "bad" rate was 0, 8.0%, 10.0%, 14.3% and 28.6% in the group of nasalization surgery, and was 0, 27.3%, 18.8%, 33.3% and 55.6% in the partial reboot surgery group, respectively. The average percentage of tissue eosinophil counts in the 72 cases was 42.1%, which had no obvious effect on the status of the surgical cavity ( P>0.05). Conclusions:For eCRSwNP patients, the operative cavity status in the patients without previous operation history treated with nasalization surgery is good. The time of 1-2 years after surgery is the main period for sinus lesions. The counts of tissue eosinophils has no significant influence on surgical sinus cavity status in the eCRSwNP patients.