Designs, Experiments, and Applications of Multichannel Structures for Hearing Aids

The structures of common multichannel processing for hearing aids include equal bandwidth (BW) finite impulse response (FIR) filter bank, nonuniform BW FIR filter bank, and fast Fourier transform (FFT) plus inverse FFT (IFFT). This paper analyzes their operation principles, indicates the design methods by means of MATLAB R2018b resources, and describes the main characteristics: synthetical ripple, bank filters’ group delays, and individual filter sidelobe attenuation. Three schemes are proposed: equal BW sixteen-filter bank, logarithmic BW eight-filter bank, and 128-point FFT plus IFFT with overlap-add operation. To build the experimental modules, we introduce the settings of spectrum scopes, the acquirement of realistic speech and noises, and the gain enhancing/reducing needs of hearing aid features; the characteristics of synthetical outputs confirm precise control ability of the multichannel modules and differences between the three schemes. Subsequently, this paper illustrates two applications of the multichannel structures in hearing aids, the equal BW sixteen-filter bank with spectral subtraction (SS) for an artificial intelligence (AI) noise reduction (NR) and 128-point FFT plus IFFT spectral distortion removal for a directional microphone (DM). In Amy’s speech mixed with ringing, milk steamer, and strong wind noises separately, the SS processor improves signal-noise-ratio (SNR) by 6.5 to 15.9 dB. By measuring waveforms and spectra at the DM input and output, the DM system seamlessly removes the spectral distortion.

Multichannel synchrosqueezing generalized S-transform for time-frequency analysis of seismic traces

The synchrosqueezing generalized S-transform (SSGST) is commonly used to generate an isofrequency component of a signal by squeezing the decomposed frequency components of the signal. However, for seismic signals, the single-trace process can have a lack of lateral information in the squeezed results and lead to some discontinuous geologic information that will mislead the interpreter. Thus, to improve the stability of SSGST, we have developed a multichannel seismic trace squeezing method. Multichannel SSGST (MSSGST) considers the decomposed frequency components of neighboring traces of the analysis seismic trace and then reconstructs the center trace. Therefore, compared with SSGST, the multichannel processing improves the stability of the squeezing and produces more laterally continuous results that properly follow the geologic phenomenon. The effectiveness of MSSGST is validated using various field data. We use the application to demonstrate the potential of multichannel squeezing to perform well at (1) improving the energy focusing and continuity of the decomposed frequency components, (2) depicting the boundaries of geologic structures, and (3) identifying the thin layers.

A New Concept of GPU-Accelerated On-Board Visual System for Aerial Vehicles

As technology advances, the level of intellectual ability and autonomy of the electronic-mechanical control system of modern aircrafts and spacecrafts is constantly growing, which helps to reduce the crew load and accident rate. But these helpful controlling systems are not perfect, under some unfavorable circumstances they get stuck or start to function unpredictably when faced with a much more complicated real situation than the developers expected, sometimes even lead to crashes. The concept of visual multichannel processing support of aircraft/spacecraft launch and landing as an additional element of automatic control loop for flight safety and reliability improvement is proposed and its advantages, feasibility and expediency are discussed and evaluated. The visual analyzers are very typical for the overwhelming majority of highly organized organisms (humans, animals, insects) as the most informative source of control of movement parameters, so they potentially can effectively improve the reliability of the entire embedded vehicle controlling system and, at the same time, their principal structure, implementation and further functioning are very similar and universal for real flight operation of different vehicles, which opens up great prospects for their application in engineering based on modern revolutionary achievements in the field of methodology and computational technologies for pattern recognition. In particular, it was shown that the required for real vehicles accuracy and productivity can be reached in case of developing the visual multichannel system, as an additional source of flight state information, on the base of NVIDIA Jetson embedded portable low power consuming Graphics processing unit (GPU)-accelerated massively parallel computational platform, providing CUDA and Artificial Intelligence data processing in real-time mode.

Исследование радиофотонного принципа построения реактивного блокиратора радиоуправляемых взрывных устройств

A new approach to design an ultra-wideband jammer of radio-controlled explosive devices, in which a multichannel processing unit based on a set of narrowband radio-signal receiving channels with the introduction of noise interference into each channel is replaced by a single-channel microwave-photonics analogue using an optoelectronic radio-signal processor based on an optical recirculation circuit to suppress the channel of the firing code transmission, is proposed and preliminarily investigated. The layout and results of computer simulation for the proposed optoelectronic processor when transmitting standard telecommunication radio signals that confirm the possibility and determine the basic conditions for blocking a radio channel, are highlighted.