Visualization of latent components assessed in O*Net occupations (VOLCANO): A robust method for standardized conversion of occupational labels to ratio scale format.

Occupations are typically characterized in nominal form, a format that limits options for hypothesis testing and data analysis. We drew upon ratings of knowledge, skills, and abilities for 966 occupations listed in the US Department of Labor's Occupational Classification Network (O*NET) database to create an accessible, standardized multidimensional space in which occupations can be quantitatively localized and compared. Principal component analysis revealed that the occupation space comprises three main dimensions that correspond to (1) the required amount of education and training, (2) the degree to which an occupation falls within a science, technology, engineering, and mathematics (STEM) discipline versus social sciences and humanities, and (3) whether occupations are more mathematically or health related. Additional occupational spaces reflecting cognitive versus labor-oriented categories were created for finer-grained characterization of dimensions within occupational sets defined by higher or lower required educational preparation. Data-driven groupings of related occupations were obtained with hierarchical cluster analysis (HCA). Proof-of-principle was demonstrated with a real-world dataset (470 participants from the Nathan Kline Institute - Rockland Sample; NKI-RS), whereby verbal and non-verbal abilities-as assessed by standardized testing-were related to the STEM versus social sciences and humanities dimension. Visualization of Latent Components Assessed in O*Net Occupations (VOLCANO) is provided to the research community as a freely accessible tool, along with a Shiny app for users to extract quantitative scores along the relevant dimensions. VOLCANO brings much-needed standardization to unwieldy occupational data. Moreover, it can be used to create new occupational spaces customized to specific research domains.

Wireless And Portable Daily Soundscape Monitoring System For Auditory Profiling: Diagnostic Tool For Alzheimer's Disease.

The purpose of this paper is to develop an inexpensive, wearable, and portable monitoring system with wireless capabilities for signal acquisition of the user's surrounding soundscape and electroencephalography (EEG). The end-goal of this device is to monitor high-risk populations that are developing into earlier stages of Alzheimer's Disease (AD). Currently, the development of such device is still within preliminary phase and has only been tested in healthy individuals. Future applications of our monitoring system may be used as a non-invasive and inexpensive diagnostic tool for early detection of AD, potentially paving a new platform for therapeutic intervention. The system consists of low-weight bearing components, including an analog front-end and a single-board computer. The analog front-end contains three independent EEG, reference, bias, and auditory recording channels. The single-board computer timestamps and encrypts the incoming channels prior to local or "cloud" storage. Cloud storage provides ease-of-access and offline data analysis without the need to physically extract the data from the monitoring system. A portable/rechargeable battery provides power to the entire monitoring system for over 4 hours of operation. A graphical user-interface (GUI) was developed for secured remote access to data, parameter settings, and system configurations. The performance of the system was tested by measuring the frequency following response (FFR) in the captured EEG signals with respect to periodic auditory stimuli.

Order selection of the hearing aid Feedback Canceller filter based on its impulse response energy.

Numerous methods have been proposed to cancel the unpleasant effects of acoustic feedback between the loudspeaker and microphone in hearing aid systems. Adaptive Feedback Cancellation (AFC) methods are often used to estimate an FIR filter for cancelling the feedback path effect. In estimating the AFC FIR filter, it is important to select the order of the filter properly; especially when the feedback path changes from one environment to another and no knowledge about it is available. Choosing improper filter order causes deficient system performance or excessive computations and power usage in the system. We present tracking of the energy of AFC FIR filters and its convergence behavior as a new criterion for determining the proper order for AFC FIR filter. Experimental results show validity of the proposed criterion.

Improving misalignment for feedback path estimation in hearing aid by multiple short-time noise injections.

Adaptive Feedback Cancellation (AFC) methods are used to find an FIR filter to cancel the negative effect of acoustic feedback between the loudspeaker and microphone of the hearing aid. Finding the AFC filter of appropriate order/length directly affects the performance and complexity of the system. In this paper, we use noise injection method to find the AFC filter estimating the feedback path model. We show that the optimum length which guarantees a good compromise between the quality and the complexity of the system may be smaller than the length of the actual feedback path model. However, in order to improve the performance of the system in terms of Misalignment criterion, we propose using multiple short-time noise injections and averaging method to find the best filter estimate of appropriate length.

Evaluation of a new approach for speech enhancement algorithms in hearing aids.

Several studies on hearing impaired people who use hearing aid reveal that speech enhancement algorithms implemented in hearing aids improve listening comfort. However, these algorithms do not improve speech intelligibility too much and in many cases they decrease the speech intelligibility, both in hearing-impaired and in normally hearing people. In fact, current approaches for development of the speech enhancement algorithms (e.g. minimum mean square error (MMSE)) are not optimal for intelligibility improvement. Some recent studies investigated the effect of different distortions on the enhanced speech and realized that by controlling the amplification distortion, the intelligibility improves dramatically. In this paper, we examined, subjectively and objectively, the effects of amplification distortion on the speech enhanced by two algorithms in three background noises at different SNR levels.

Adaptive cancellation of variable feedback path for hearing aid using misalignment-dependent step size values.

Various methods have been proposed to overcome the problem of compensating the acoustic feedback path that negatively impacts the performance of hearing aid devices. However, in most of them feedback path model is assumed to be fixed which is not quite realistic. In this paper, we consider fixed and variable feedback paths and analyze for each case the performance of one of the robust Adaptive Feedback Cancellation (AFC) schemes, i.e. the Prediction Error Method AFC which uses Partitioned Block Frequency-Domain Normalized Least Mean Square (PBFD-NLMS) algorithm. Based on the analysis results we propose varying the step size values for the same adaptive algorithm on the fly by monitoring the misalignment criteria. The experimental results using the proposed method show improvement made on the system performance.

A new delayless sub-band filtering method for cancelling the effect of feedback path in hearing aid systems.

Performance of commonly used Hearing aid systems is degraded by the presence of acoustic feedback between loudspeaker and microphone. Prediction Error Method Adaptive Feedback Canceller (PEM-AFC) has been proposed recently that could attenuate the feedback effect. In this paper, we present a new delayless frequency-based sub-band filtering method for alleviating the effect of feedback path for the Hearing aid systems. The proposed method avoids sub-band distortions and has low computational complexity making it suitable for low-power cost-effective hearing aid system designs. Performances of the two methods are compared and simulation results are presented.