GN Store Nord (Denmark)

This study aimed to investigate the effects of hearing aids (HAs) on reducing symptoms of dizziness in patients with hearing loss (HL) and dizziness. Subjects and. A pre- and post-intervention study was conducted between February 2022 and July 2022 at the outpatient clinic of a tertiary hospital in Seoul, South Korea. Ten participants (four males and six females) with HL and dizziness were recruited. Participants were screened using pure-tone audiometry and visual analog scale scores at baseline. Selected participants underwent the Modified Clinical Test of Sensory Interaction on Balance (mCTSIB) and Korean Dizziness Handicap Inventory (K-DHI) in the unaided state. Thereafter, participants were provided HAs and instructed to use them for at least 6 hours every day. At the 1-month follow-up, all participants were assessed in the aided state using the same tests as at baseline. All tests were performed bilaterally. In the mCTSIB, a significant difference was observed in the foam surface-eyes closed score before (median=2.35) and after (median=2.2) HA use (p=0.049). No significant differences were observed in the K-DHI scores before and after HA use. HA use may improve the static and subjective perception of balance in patients with HL and dizziness. Future research should explore the benefits of HAs under various balance conditions such as dynamic balance and gait.

The topic of deep acoustic echo control (DAEC) has seen many approaches with various model topologies in recent years. Convolutional recurrent networks (CRNs), consisting of a convolutional encoder and decoder encompassing a recurrent bottleneck, are repeatedly employed due to their ability to preserve nearend speech even in double-talk (DT) condition. However, past architectures are either computationally complex or trade off smaller model sizes with a decrease in performance. We propose an improved CRN topology which, compared to other realizations of this class of architectures, not only saves parameters and computational complexity, but also shows improved performance in DT, outperforming both baseline architectures FCRN and CRUSE. Striving for a condition-aware training, we also demonstrate the importance of a high proportion of double-talk and the missing value of nearend-only speech in DAEC training data. Finally, we show how to control the trade-off between aggressive echo suppression and near-end speech preservation by fine-tuning with condition-aware component loss functions.

A highly sophisticated ray-based propagation model is used to find the optimal on-body radiation pattern for an ear-to-ear link. The propagation model allows for a rapid evaluation of the path gain given the antenna radiation patterns. The radiation patterns are represented by the spherical wave expansion (SWE) since they are easy to handle in the computer and in addition the expansion coefficients separate one antenna from another. Furthermore, the SWE produces physically realizable radiation patterns. The procedure to obtain the optimal radiation patterns is formulated as evolution-based optimization. It is found that the optimal gain pattern directs the power in the directions of the geodesic paths traced by the model that lead from one ear to the other. This is in accordance with expectations. The optimized path gain is -35.0 dB, which is obtained with lossless antennas with a minimum sphere of 0.2 free-space wavelengths.

Directionality is the only hearing aid technology — in addition to amplification — proven to help hearing aid users hear better in noise. Hearing aid directionality has been documented to improve speech intelligibility in multiple laboratory studies. In contrast, real-world studies have shown a disconnect between the potential of the technology and what hearing aid users experience in their daily life. This article describes the real-world studies that inspired ReSound to take a different approach to applying directional microphone technology. This approach is based on the idea that hearing aid directionality can leverage natural binaural hearing and inherent listening strategies. The directional strategy includes three listening modes that will be explained. These are the Spatial Cue Preservation mode, the Binaural Listening mode, and the Speech Intelligibility mode. The strategy and the advantages it provides in terms of sound quality, spatial hearing, and improved signal-to-noise ratio with maintained awareness of surroundings are explained.

This paper provides a small set of essential parameters for a personalized and effective real-time auralization with headphones. An image-guided procedure with two 2D images of the user’s head guides the mixed structural modeling of head-related transfer function (HRTF), combining a spherical head model with ear displacement with the HRTF high-frequency magnitude selected from a database according to ear anthropometry. Room acoustics phenomena are simplified following the scattering delay network (SDN) approach which allows an accurate spatialization of first order reflections. Finally, statically significant improvements in localization performances within a virtual reality (VR) test allow to identify some benefits of the proposed customized auralization model compared to the widely used higher-order ambisonics (HOA) rendering with generic HRTFs.

Enhancement of speech in non stationary noise environments has been a major research topic due to its wide range of applications, e.g., in hearing aids. This paper proposes a method for performing dual channel speech enhancement. The proposed method involves the estimation of speech and noise short term predictor (STP) parameters using a codebook based approach, when we have access to binaural noisy signals. The estimated STP parameters are subsequently used for enhancement in a dual channel scenario. Objective measures indicate, that the proposed method is able to improve the speech intelligibility and quality.

Many articles on on-body propagation assumes that the human body can be approximated by a perfect electric conductor (PEC) instead of the actual constitutive parameters of the human body, which is that of a lossy dielectric. This assumption is investigated in this article through comparison of the scattering of a plane wave at oblique incidence by a PEC and a lossy dielectric cylinder. The investigation shows that the validity of the assumption depends on the polarization of the plane wave, the angle of incidence, and the region of interest.

A novel in-the-ear antenna for hearing instruments that operates at 2.45 GHz is presented. The antenna is designed to obtain a polarization perpendicular to the surface of the head in order to optimize the ear-to-ear communication. The antenna consists of a bent dipole with a shorting pin used for impedance matching. It is self-resonant and well matched in the entire Industrial, Scientific, and Medical band from 2.40 to 2.48 GHz. The simulated and measured peak ear-to-ear path gain $|S_{21}|$ is $-\text{74.5}$ and $-\text{72.9}$ dB, respectively. The radiation pattern of the antenna is analyzed, and the implications of the radiation pattern on the ear-to-ear communication are discussed.

In this paper we present an analysis of the behaviour of a 2.4 GHz Low Noise Amplifier (LNA) for Wireless Body Area Network (WBAN) applications facing antennadetuning issue. An amplifier with ultra-low power, low voltage, and with reduced component count is prototyped to validate simulation results, then the behaviour is analyzed through simulations based on data measured on real users. The analysis shows that the designed LNA is stable to the antenna impedance variation expectable in most cases, while highlights the possible risks associated to a high-Q input matching network when used in a context prone to antenna detuning risk.

Feedback whistling is a severe problem with hearing aids. A typical acoustical feedback path represents a wave propagation path from the receiver to the microphone and includes many complicated effects among which some are invariant or nearly invariant for all users and in all acoustical environments given a specific type of hearing aids. Based on this observation, a feedback path model that consists of an invariant model and a variant model is proposed. A common-acoustical-pole and zero model-based approach and an iterative least-square search-based approach are used to extract the invariant model from a set of impulse responses of the feedback paths. A hybrid approach combining the two methods is also proposed. The general properties of the three methods are studied using artificial datasets, and the methods are cross-validated using the measured feedback paths. The results show that the proposed hybrid method gives the best overall performance, and the extracted invariant model is effective in modeling the feedback path.