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A new method for measurement of impulsive peak level attenuation of hearing protectors

ASA/ANSI S12.42-2010 contains the first standardized test method for measuring the performance of hearing protection devices (HPDs) with high-level impulsive noise. This standard defines the impulsive peak insertion loss (IPIL) as a time-domain metric that quantifies the reduction in peak sound pressure level provided by an HPD for impulsive noises. However, IPIL as defined in S12.42-2010 is dependent on the spectrum of the impulsive noise source used for measurements of HPDs. Recent studies of HPDs with impulsive noise have led to the investigation of frequency-domain metrics and calculation methods. Using frequency-domain calculations allows the impulsive peak level attenuation to be computed for a wide range of impulsive noises, not only those used for the measurement. Consequently, significant revisions to S12.42 are under consideration and a new standard, ISO 4869-7, is being developed in parallel with the ANSI revision. This presentation highlights key proposals and substantive changes including: measurement and calculation of the frequency-dependent impulsive insertion loss (IIL), incorporation of frequency-domain aspects such as real-ear attenuation at threshold (REAT) limits to attenuation, and a new impulsive peak level attenuation metric (IPLA) to be calculated from the REAT-bounded IIL.

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Reducing Data Requirements for Wiener Series Identification With Gaussian Process Priors

Abstract System identification of nonlinear dynamical systems aims to predict the output of a system for a given input. In many engineering applications, the underlying physics are not fully understood and so there is no analytical solution. The Wiener series is a classical data-driven technique that decomposes the system response into a set of orthogonal functionals of increasing order. Unlike standard black-box algorithms, such as neural networks, the series is highly interpretable and can offer insight into the nonlinearities present. To date, in order to calculate higher order terms in the Wiener series, vast quantities of data are needed. In this paper, a novel formulation of the Wiener series is developed in the frequency domain which applies to general stochastic inputs with an arbitrary spectrum. It is enhanced by placing Gaussian process priors over the Wiener kernels to enforce prior knowledge of their structure. This significantly reduces the quantity of data required for inference and has the benefit of enabling the calculation of the third order kernel for systems with long memory. The benefits were demonstrated in initial investigations using an idealised nonlinear oscillatory system. Decomposition of the system response into Wiener functionals also sheds light on the learnability of nonlinear dynamical systems, which could be used to assess the value of collecting additional data.

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HiSSNet: Sound Event Detection and Speaker Identification via Hierarchical Prototypical Networks for Low-Resource Headphones

Modern noise-cancelling headphones have significantly improved users’ auditory experiences by removing unwanted background noise, but they can also block out sounds that matter to users. Machine learning (ML) models for sound event detection (SED) and speaker identification (SID) can enable headphones to selectively pass through important sounds; however, implementing these models for a user-centric experience presents several unique challenges. First, most people spend limited time customizing their headphones, so the sound detection should work reasonably well out of the box. Second, the models should be able to learn over time the specific sounds that are important to users based on their implicit and explicit interactions. Finally, such models should have a small memory footprint to run on low-power headphones with limited on-chip memory. In this paper, we propose addressing these challenges using HiSSNet (Hierarchical SED and SID Network). HiSSNet is an SEID (SED and SID) model that uses a hierarchical prototypical network to detect both general and specific sounds of interest and characterize both alarm-like and speech sounds. We show that HiSSNet outperforms an SEID model trained using non-hierarchical prototypical networks by 6.9 – 8.6%. When compared to state-of-the-art (SOTA) models trained specifically for SED or SID alone, HiSSNet achieves similar or better performance while reducing the memory footprint required to support multiple capabilities on-device.

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A new adaptive differential evolution-hybrid fuzzy PIDN controller for performance amelioration of power systems

Abstract Rapidly returning back the synchronism of an inter-connected multi-area power system under continuous varying load demand conditions is documented as a distinguished issue to be tackled by automatic generation control (AGC). AGC supports to alleviate both the frequency and tie-line power deviations on occurrence of load perturbations. Therefore, a robust and intelligent controller is indispensable for an effective AGC in power system. In the current work, a hybrid fuzzy proportional-integral-derivative with filter (FPIDN) controller is employed for AGC of 2-area non-reheat/reheat thermal power systems. A new adaptive differential evolution (ADE) is exploited to adjust parameters of the controller. The dominance of the endorsed technique is revealed by evaluating it with lately published approaches. Then, the recommended scheme is extended to a realistic 4-area interconnected reheat thermal system, which includes all possible uncertainties such as generation rate constraint, boiler dynamics and governor dead band. It is perceived that the performance of the suggested ADE aided hybrid FPIDN controller provides a better response than other control techniques. Lastly, the robustness of the advocated method is tested for an extensive variety of system parameters. The stability analysis is validated by analyzing frequency domain specifications such as gain margin and phase margin. Finally, real-time hardware-in-the-loop simulations are performed to confirm the applicability of the advocated controller for AGC.

Open Access
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