scholarly journals The Effects of Dynamic-range Automatic Gain Control on Sentence Intelligibility With a Speech Masker in Simulated Cochlear Implant Listening

2019 ◽  
Vol 40 (3) ◽  
pp. 710-724 ◽  
Author(s):  
Nathaniel J. Spencer ◽  
Kate Helms Tillery ◽  
Christopher A. Brown
Keyword(s):  
Cochlear Implant ◽  
Dynamic Range ◽  
Automatic Gain Control ◽  
Gain Control ◽  
Sentence Intelligibility

scholarly journals Effect of (Mis)Matched Compression Speed on Speech Recognition in Bimodal Listeners

2020 ◽  
Vol 24 ◽  
pp. 233121652094897
Author(s):  
Dimitar Spirrov ◽  
Eugen Kludt ◽  
Eline Verschueren ◽  
Andreas Büchner ◽  
Tom Francart
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Dynamic Range ◽  
Automatic Gain Control ◽  
Hearing Aid ◽  
Gain Control ◽  
Time Constants ◽  
Hearing Devices ◽  
Testing Condition ◽  
Speech Recognition In Noise

Automatic gain control (AGC) compresses the wide dynamic range of sounds to the narrow dynamic range of hearing-impaired listeners. Setting AGC parameters (time constants and knee points) is an important part of the fitting of hearing devices. These parameters do not only influence overall loudness elicited by the hearing devices but can also affect the recognition of speech in noise. We investigated whether matching knee points and time constants of the AGC between the cochlear implant and the hearing aid of bimodal listeners would improve speech recognition in noise. We recruited 18 bimodal listeners and provided them all with the same cochlear-implant processor and hearing aid. We compared the matched AGCs with the default device settings with mismatched AGCs. As a baseline, we also included a condition with the mismatched AGCs of the participants’ own devices. We tested speech recognition in quiet and in noise presented from different directions. The time constants affected outcomes in the monaural testing condition with the cochlear implant alone. There were no specific binaural performance differences between the two AGC settings. Therefore, the performance was mostly dependent on the monaural cochlear implant alone condition.

scholarly journals Photodetector resistant to background light noise with extended dynamic range of input signals

2021 ◽  
pp. 3-8
Author(s):  
V. M. Lipka ◽  
V. V. Ryukhtin ◽  
Yu. G. Dobrovolsky
Keyword(s):  
Dynamic Range ◽  
Automatic Gain Control ◽  
Modulation Frequency ◽  
Low Frequency ◽  
Gain Control ◽  
Ambient Air ◽  
Frequency Range ◽  
Background Light ◽  
Useful Signal ◽  
Extended Dynamic

Measurement of periodic optical information signals in the background light noise with a photodetector with extended dynamic range is an urgent task of modern electronics and thus has become the aim of this study. To increase the dynamic range of the photodetector, a new version of the automatic gain control (AGC) circuit has been developed, which consists of an AGC controller, an output photodetector amplifier and an AGC detector. The authors measured the dynamic range of the photodetector when receiving optical radiation with a wavelength of 1064 nm in the power range from 2.10–8 to 2.10–5 W at a modulation frequency of 20 kHz with the AGC on. Under these conditions, the dynamic range of the photodetector was found to be up to 67 dB. If the AGC was off, the dynamic range did not exceed 30 dB. Thus, the study made it possible to create a photodetector with an extended dynamic range up to 67 dB based on a new version of the AGC circuit. The design of the photodetector allowed choosing a useful signal of a particular modulation frequency in the frequency range from 3 to 45 kHz and effectively suppresses the frequencies caused by optical interference in the low frequency range from the frequency of the input signal of constant amplitude up to 3 kHz inclusive. This compensates the current up to 15 mA, which is equivalent to the power of light interference of about 15 mW. Further research should address the issues of reliability of the proposed photodetector design and optimization of its optical system. The photodetector can be used in geodesy and ambient air quality monitoring.

scholarly journals 14.85 µW Analog Front-End for Photoplethysmography Acquisition with 142-dBΩ Gain and 64.2-pArms Noise

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 512
Author(s):  
Binghui Lin ◽  
Mohamed Atef ◽  
Guoxing Wang
Keyword(s):  
Dynamic Range ◽  
Automatic Gain Control ◽  
Gain Control ◽  
Low Noise ◽  
Total Power ◽  
Cmos Process ◽  
Control Block ◽  
Silicon Area ◽  
Front End ◽  
Analog Front End

A low-power, high-gain, and low-noise analog front-end (AFE) for wearable photoplethysmography (PPG) acquisition systems is designed and fabricated in a 0.35 μm CMOS process. A high transimpedance gain of 142 dBΩ and a low input-referred noise of only 64.2 pArms was achieved. A Sub-Hz filter was integrated using a pseudo resistor, resulting in a small silicon area. To mitigate the saturation problem caused by background light (BGL), a BGL cancellation loop and a new simple automatic gain control block are used to enhance the dynamic range and improve the linearity of the AFE. The measurement results show that a DC photocurrent component up-to-10 μA can be rejected and the PPG output swing can reach 1.42 Vpp at THD < 1%. The chip consumes a total power of 14.85 μW using a single 3.3-V power supply. In this work, the small area and efficiently integrated blocks were used to implement the PPG AFE and the silicon area is minimized to 0.8 mm × 0.8 mm.

scholarly journals Improving Localization and Speech Reception in Noise for Bilateral Cochlear Implant Recipients

2019 ◽  
Vol 23 ◽  
pp. 233121651983149 ◽  
Author(s):  
Wendy B. Potts ◽  
Lakshmish Ramanna ◽  
Trevor Perry ◽  
Christopher J. Long
Keyword(s):  
Cochlear Implant ◽  
Automatic Gain Control ◽  
Gain Control ◽  
Interaural Level Difference ◽  
Mean Square ◽  
Localization Accuracy ◽  
Speech In Noise ◽  
Speech Reception ◽  
Bilateral Cochlear Implant ◽  
Comparative Survey

This study looked at different methods to preserve interaural level difference (ILD) cues for bilateral cochlear implant (BiCI) recipients. One possible distortion to ILD is from automatic gain control (AGC). Localization accuracy of BiCI recipients using default versus increased AGC threshold and linked AGCs versus independent AGCs was examined. In addition, speech reception in noise was assessed using linked versus independent AGCs and enabling and disabling Autosensitivity™ Control. Subjective information via a diary and questionnaire was also collected about maps with linked and independent AGCs during a take-home experience. Localization accuracy improved in the increased AGC threshold and the linked AGCs conditions. Increasing the AGC threshold resulted in a 4° improvement in root mean square error averaged across all speaker locations. Using linked AGCs, BiCI participants experienced an 8° improvement for all speaker locations and a 19° improvement at the speaker location most affected by the AGC. Speech reception threshold in noise improved by an average of 2.5 dB when using linked AGCs versus independent AGCs. In addition, the effect of linked AGCs on speech in noise was compared with that of Autosensitivity™ Control. The Speech, Spatial, and Qualities of Hearing Scale-12 question comparative survey showed an improvement when using maps with linked AGCs. These findings support the hypothesis that ILD cues may be preserved by increasing the AGC threshold or linking AGCs.

Matching Automatic Gain Control Across Devices in Bimodal Cochlear Implant Users

2016 ◽  
Vol 37 (3) ◽  
pp. 260-270 ◽  
Author(s):  
Lidwien C. E. Veugen ◽  
Josef Chalupper ◽  
Ad F. M. Snik ◽  
A. John van Opstal ◽  
Lucas H. M. Mens
Keyword(s):  
Cochlear Implant ◽  
Automatic Gain Control ◽  
Gain Control

An Optimized Design Strategy for the Hardware Implementation of the Hearing Aid Algorithms

2015 ◽  
Vol 719-720 ◽  
pp. 548-553
Author(s):  
Feng Guo ◽  
Shan Shan Yong ◽  
Zhao Yang Guo ◽  
Xin An Wang ◽  
Guo Xin Zhang
Keyword(s):  
Hardware Implementation ◽  
Dynamic Range ◽  
Automatic Gain Control ◽  
Hearing Aid ◽  
Gain Control ◽  
Design Strategy ◽  
Optimized Design ◽  
Wide Dynamic Range ◽  
Dynamic Range Compression ◽  
The Common

In this paper, a new design strategy for the hardware implementation of hearing aid algorithms is proposed. Two familiar hearing aid algorithms—Wide Dynamic Range Compression (WDRC) and Automatic Gain Control (AGC)—are implemented in one circuit as an example. By putting the common arithmetic procedures into common module, the operation units can be used repeatedly. In this way, the area and power consumption are visibly reduced.

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