WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653

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  • Article
    Investigation of Factors Affecting Noise Robustness in Voice Activity Detectors
    (Gazi Univ, Fac Engineering Architecture, 2023) Ozaydin, Selma
    In this manuscript, some voice activity detectors (VADs) in the literature were examined in terms of factors affecting their robustness under different acoustic noise conditions and in this context, the changes in detection accuracy rates according to changing noise conditions were tested. In this scope, the effect of situations such as whether the threshold value used in the decision phase in VAD methods is fixed or adaptive, the analysis window is short or long, the use of more than one feature vector together has been evaluated and analyzed comparatively. While three of the four different VAD detectors examined in this manuscript use feature vectors within the short-term analysis window while generating the decision result, one decides according to the measurement result of long-term spectral vectors. The VAD detectors in the article have been tested using the NOIZEUS noisy speech database. Thus, the performance of the analyzed VADs has been evaluated under different acoustic conditions using an extensive database that has already taken place in the literature. During the testing of the analyzed VADs, different input noise speech signals with environmental background noises between [15-0dB] such as restaurant, car, street, or station were tested. Tests were carried out using objective test measurement methods and the detection accuracy rate of each VAD method was measured. The results showed that each method gave different endurance performance in adverse environmental conditions.
  • Article
    Citation - WoS: 1
    Effects of Sound Absorption Materials on Reverberation Time According To Their Positions in the Square Plan and High Ceiling Rooms
    (Gazi Univ, Fac Engineering Architecture, 2021) Kurtay, Cuneyt; Harputlugil, Gulsu Ulukavak; Yaman, Muammer
    In rooms with speech action, subjective and objective room acoustics parameters should be considered in the creation of acoustic performance. In this study, an evaluation has been made over the reverberation time for the speech action of the existing Iraq-Najaf Islamic University Alawiya Conference Hall. Within the scope of the study, the control of the reverberation time affecting the subjective and objective room acoustics parameters has been examined, the relationship between the reverberation time and the surface absorptions of the room have been examined. Reverberation time on existing situation was determined by making in situ measurements. In order to control the reverberation time of the existing hall, the materials selected according to the sound absorption coefficients have been positioned differently and alternative models have been developed. The reverberation times of the alternative models were determined using the ECOTECT v.5.20 computer simulation program used for acoustic analysis, and their geometric acoustics analysis was performed using the ray tracing method. By comparing the models, the surface absorptions have been analyzed to obtain the appropriate reverberation time in room for speech action. As a result of the study, the effects of the use of walls, ceiling and floor finishing materials and surface absorptions on the reverberation time have been evaluated within the scope of improvement for speech action in the halls with square plan, flat floor and high ceiling (min 6 m).