Difference between PDT-EC and PDT-E

Difference between PDT-EC and PDT-EAS depends on applying the devices. In partial deafness treatment with an electrical complement (PDT-EC) only the speech processor was used but for group of patients referred for electric and acoustic stimulation (PDT-EAS) the first step is used a hearing aid and the next applying a Duet or Hybrid system (Lorens et al., 2012; Skarzynski et al., 2006, 2007). The aim of this study was to assess preoperative threshold and postoperative results of hearing preservation in two groups. The first group (PDT-EC) included 31 patients and second 43 in years 2002–2012 (Skarzynski, 2012).The analysis of results (Fig. 13.8) indicates that thresholds during 10 years observation were stable. No significant deterioration of hearing level at low frequencies in the first operated PDT-EC group was observed. The data from Figure 13.9 shows that 6 months after operation the thresholds at the low frequencies deteriorated about 10–25 dB, however the hearing levels above 1000 Hz are on stable. Significant hearing deterioration from 1 month to 6 months after surgery is difficult to explain.Our observations indicated that 32.5 % of patients reported that the hearing in nonimplanted ear was worsened. The most important results are presented in Figures 13.10 and 13.11 showing that systematic rehabilitation process may impact significant on speech perception. The higher level of results speech perception in quiet and noise were observed in PDT-EC group (Skarzynski, 2012).