Effective Gain Research Articles

The Hannover Coupler V2: Audiological outcomes of a round window coupler for the Vibrant Soundbridge.

IntroductionThe Hannover Coupler version 2 (HC2) was designed to (1) adapt the coupler geometry to the round window (RW) niche (2) to stabilize the floating mass transducer, and (3) to control static coupling forces to the RW. First audiological outcomes with a custom‐made HC2 are reported here.Material and MethodsTen patients were enrolled in our site‐initiated, prospective study. To assess audiological outcomes up to 6 months, preoperative and postoperative hearing thresholds, word recognition score (WRS) at 65 dB SPL and the speech recognition threshold in quiet and noise were performed. The effective gain (EG) and the coupling efficiency were calculated.ResultsOne revision surgery had to be performed during the study period and a significant, but clinically not relevant bone conduction thresholds change was observed at 4 and 6 kHz at 6‐month follow‐up. At 6 months, the median WRS (n = 10) improved significantly from 0% to 80%. The median speech reception threshold in noise improved significantly from 11.6 to −2.4 dB SNR, and in quiet significantly from 79.6 to 44.4 dB SPL. The average EG of −1.3 dB indicated a closure of the air bone gap. The determined average coupling efficiency of 23.3 dB was within the acceptance range suggested by the manufacturer.ConclusionFor patients with mixed hearing loss and multiple ear surgeries, the HC2 provided good and stable speech recognition results exceeding published results of RW coupling without a coupler or coupling with the RW soft coupler.

Effective Gain Analysis and Statistic Based Calibration for Ring Amplifier With Robustness to PVT Variation

This brief focuses on the robustness of the ring amplifier (RA), an alternative to the operational transconductance amplifier (OTA) in the deep nanoscale CMOS process. The effective gain (EG) of the RA shows diverse characteristics from the DC gain and can be treated as a non-linear gain error (NLGE). The EG shows a notable variation when taking process, supply voltage, and temperature (PVT) into consideration. An improved statistical calibration based on the back-end stage data is proposed to compensate the NLGE. A prototype SAR-assisted pipeline ADC with a quick-start RA is implemented in a 28-nm CMOS process, achieving 60.3 dB SNDR and 76.5 dB SFDR with a 6 MHz input at 625 MS/s. The SNDR and SFDR are 58.6 dB and 70.7 dB with a Nyquist input frequency and consumes 13.2 mW, achieving Walden and Schreier figure-of-merit (FoM) values of 30.4 fJ/conv.-step and 162.2 dB. For a −6 dBFS 50 MHz input, the measured SNDR and SFDR are above 55.5 dB and 68.9 dB with supply voltage and temperature fluctuation.

Comparative analysis between effective gain and functional gain in bone-anchored hearing aid users.

The cases of ear malformations, conductive, mixed, and single-sided deafness hearing loss are candidates for surgery and use of Bone-Anchored Hearing Aids (BAHA). Commonly, the literature highlights two procedures to assess the benefits and characteristics of amplification in users: functional gain (FG) and effective gain (EG). Estimate and compare the EG and the FG to evaluate the benefits obtained by users of BAHA and, later, to compare tests of speech perception in silence and in noise. The sample (n=79) was divided into four groups, implanted from February 2014 to February 2021. The following tests were analyzed: pure-tone audiometry by air and bone; research of audiometric thresholds in free field; speech perception tests in silence and in noise. EG presented lower values than FG in all frequencies. The positive results of the speech perception tests were correlated with worse FG values. EG is the best method for evaluation, as it allows a proper comparison between devices, as well as a comparison with the prescription of validated rules. A better evaluation of results was observed on the EG values, indicating that it is a relevant method to assess auditory performance. In addition, the FG results were incompatible with the benefits obtained in the speech perception tests, showing that it is not a reliable tool for monitoring the results with the use of BAHA.