SPEECH-INTELLIGIBILITY AND TALKER-RECOGNITION TESTS OF AIR FORCE VOICE COMMUNICATION SYSTEMS

Author(s):  
Stephen E. Stuntz
Author(s):  
Isiaka Ajewale Alimi

Digital hearing aids addresses the issues of noise and speech intelligibility that is associated with the analogue types. One of the main functions of the digital signal processor (DSP) of digital hearing aid systems is noise reduction which can be achieved by speech enhancement algorithms which in turn improve system performance and flexibility. However, studies have shown that the quality of experience (QoE) with some of the current hearing aids is not up to expectation in a noisy environment due to interfering sound, background noise and reverberation. It is also suggested that noise reduction features of the DSP can be further improved accordingly. Recently, we proposed an adaptive spectral subtraction algorithm to enhance the performance of communication systems and address the issue of associated musical noise generated by the conventional spectral subtraction algorithm. The effectiveness of the algorithm has been confirmed by different objective and subjective evaluations. In this study, an adaptive spectral subtraction algorithm is implemented using the noise-estimation algorithm for highly non-stationary noisy environments instead of the voice activity detection (VAD) employed in our previous work due to its effectiveness. Also, signal to residual spectrum ratio (SR) is implemented in order to control the amplification distortion for speech intelligibility improvement. The results show that the proposed scheme gives comparatively better performance and can be easily employed in digital hearing aid system for improving speech quality and intelligibility.


2021 ◽  
Vol 17 (1) ◽  
pp. 11-22
Author(s):  
Wahyu Adi Prijono

Voice over Internet Protocol (VoIP) is a technology that is capable of passing voice traffic, in the form of packets through the network Internet Protocol (IP). IP network itself is a data communications network based packet-switch. The voice signal before experiencing bundled voice coding or format conversion of sound into digital form that can be passed over an IP network. Telephony, Internet telephony, or termed VoIP (Voice Over Internet Protocol.This communication system use VoIP (Voice over Internet Protocol), ie voice calls over data services (internet). This communication was developed using Android-based devices. Based on characteristics, android devices are open source, so users do not need to have a license to be able to have android-based devices. In addition, the android device that must be connected to a SIP (Session Iniation Protocol) is a data service that can be done with a paid subscription of the user of the operator using a conventional pulse. Telecommunications designed will use a hybrid system, the merger between VoIP communications with data communications GSM network. With basic calculations where Coding standards G 729, is a standard that can be used for voice communication system through data networks with rate of 8 Kbps. The implementation of the G729 codec is effect on communication systems VOIP.


2018 ◽  
pp. 125-152
Author(s):  
William D. Voiers ◽  
Alan D. Sharpley ◽  
Ira L. Panzer

Author(s):  
LUCIA JAMBOLA ◽  
ARSYAD RAMADHAN DARLIS ◽  
LITA LIDYAWATI ◽  
DZIKRI FACHRI HUSAENI

ABSTRAKSistem komunikasi suara bawah air telah dikenal sejak lama, diantaranya sonar dan akustik. Seiring perkembangan zaman dan kemajuan teknologi, kini hadir komunikasi dengan media transmisi cahaya tampak yaitu Visible Light Communication (VLC) yang dapat diterapkan pada komunikasi bawah air. Pada penelitian ini telah dilakukan komunikasi suara bawah air (simplex) menggunakan VLC, dengan media akuarium berisi air dan beberapa pengujian diantaranya menggunakan color filter, didapat hasil pengujian terbaik yaitu tegangan 4,4 Vpp dan frekuensi 3,003 kHz untuk color filter yellow, pengujian menggunakan lensa didapat hasil pengujian terbaik yaitu tegangan 4,4 Vp-p dan frekuensi 3,051 kHz untuk lensa (+50), dan pengujian terakhir menggunakan lampu UV didapat hasil pengujian terbaik dengan tegangan 4,4 Vp-p dan frekuensi 3,010 kHz. Implementasi sistem VLC ini menunjukkan hasil yang baik dan layak untuk diterapkan pada komunikasi suara bawah air (simplex).Kata kunci: VLC, Komunikasi Suara Bawah Air, Simplex. ABSTRACTUnderwater voice communication systems have been known for a long time, including sonar and acoustics. Along with the development and advancement of technology, now there is communication with visible light transmission media, namely Visible Light Communication (VLC) which can be applied to underwater communication. Under this study underwater voice communication (simplex) has been carried out using VLC, with aquarium media containing water and several tests including using a color filter, the best test results obtained are voltage 4.4 Vp-p and frequency 3.003 kHz for yellow color filter, testing using the lens obtained the best test results namely voltage 4.4 Vp-p and frequency 3.051 kHz for lenses (+50), and the last test using UV lights obtained the best test results with a voltage of 4.4 Vp-p and a frequency of 3.010 kHz. The implementation of the VLC system shows good and feasible results to be applied to underwater voice communication (simplex).Keywords: VLC, Underwater Voice Communication, Simplex.


2020 ◽  
Vol 8 (3) ◽  
pp. 197 ◽  
Author(s):  
Lovro Maglić ◽  
Sanjin Valčić ◽  
Ana Gundić ◽  
Livia Maglić

The tasks of an officer of the watch (OOW) on complex ships during navigation in coastal areas may be very challenging. Almost all the tasks require substantial information processing and timely decision making. Every distracting element should be avoided during navigation. Every call, made through any communication system, activates a new process that the OOW needs to conduct. The new process may interrupt a previously started task. In case of too many incoming calls, the workload of the OOW may increase significantly, thus, their situational awareness may be compromised and the risk of errors may increase. The objective of this research was to analyze the impact of incoming voice calls on the OOW. The research methods used include a questionnaire survey and a series of interviews with experienced officers. The main outcomes refer to the average frequency of incoming calls, duration of conversations and subjective assessment of their influence. The results indicate that, during one watch, an officer needs to answer 14 calls that last 16.19 min altogether. However, the officers consider 45% of calls made during watch keeping as distracting. A possible call management system with the aim to reduce distractions made by low priority calls is proposed in this paper.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4763
Author(s):  
Grzegorz Debita ◽  
Przemysław Falkowski-Gilski ◽  
Marcin Habrych ◽  
Grzegorz Wiśniewski ◽  
Bogdan Miedziński ◽  
...  

Application of a high-efficiency voice communication systems based on broadband over power line-power line communication (BPL-PLC) technology in medium voltage networks, including hazardous areas (like the oil and mining industry), as a redundant mean of wired communication (apart from traditional fiber optics and electrical wires) can be beneficial. Due to the possibility of utilizing existing electrical infrastructure, it can significantly reduce deployment costs. Additionally, it can be applied under difficult conditions, thanks to battery-powered devices. During an emergency situation (e.g., after coal dust explosion), the medium voltage cables are resistant to mechanical damage, providing a potentially life-saving communication link between the supervisor, rescue team, paramedics, and the trapped personnel. The assessment of such a system requires a comprehensive and accurate examination, including a number of factors. Therefore, various models were tested, considering: different transmission paths and types of coupling (inductive and capacitive), as well as various lengths of transmitted data packets. Next, a subjective quality evaluation study was carried out, considering speech signals from a number of languages (English, German, and Polish). Based on the obtained results, including both simulations and measurements, appropriate practical conclusions were formulated. Results confirmed the applicability of BPL-PLC technology as an efficient voice communication system for the oil and mining industry.


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