Perceptual Assessment

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The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform

Chengming Hsu - One of the best experts on this subject based on the ideXlab platform.

  • autologous thyroid cartilage graft implantation in medialization laryngoplasty a modified approach for treating unilateral vocal fold paralysis
    Scientific Reports, 2017
    Co-Authors: Mingshao Tsai, Mingyu Yang, Genghe Chang, Yaote Tsai, Menghung Lin, Chengming Hsu
    Abstract:

    Medialization laryngoplasty is the standard surgical treatment for unilateral vocal fold paralysis. This study presents a modified approach in which a thyroid cartilage graft is implanted in medialization laryngoplasty. 22 patients who underwent this approach were included in the study. The results revealed that glottal incompetence and vocal performance were markedly improved following surgery, and the follow-up period ranged from 6 to 74 months (mean, 21.4 months). Acoustic analysis revealed significant improvements in the maximum phonation time (from 3.51 to 7.89 seconds, p < 0.001), F0 (from 221.7 to 171.0 Hertz, p = 0.025), and jitter (from 7.68 to 3.19, p < 0.001). Perceptual Assessment revealed a significant decrease in voice grading (from 2.59 to 1.41, p < 0.001), roughness (from 1.82 to 1.23, p = 0.004), and voice breathiness (from 2.55 to 1.23, p < 0.001). None of the patients exhibited severe wound infection, tissue rejection, or other complications attributed to the surgical procedure. In conclusion, autologous thyroid cartilage implantation in medialization laryngoplasty medializes the vocal cord, minimizes the glottal gap, and improves the voice of patients with vocal fold paralysis. This procedure is characterized by simplicity, safety, and acceptable results.

Georg Meyer - One of the best experts on this subject based on the ideXlab platform.

  • Perceptual Assessment of environmental stability modulates postural sway.
    PloS one, 2018
    Co-Authors: Natalia Cooper, Iain Cant, Mark White, Georg Meyer
    Abstract:

    We actively maintain postural equilibrium in everyday life, and, although we are unaware of the underlying processing, there is increasing evidence for cortical involvement in this postural control. Converging evidence shows that we make appropriate use of ‘postural anchors’, for example static objects in the environment, to stabilise our posture. Visually evoked postural responses (VEPR) that are caused when we counteract the illusory perception of self-motion in space (vection) are modulated in the presence of postural anchors and therefore provide a convenient behavioural measure. The aim of this study is to evaluate the factors influencing visual appraisal of the suitability of postural anchors. We are specifically interested in the effect of perceived ‘reality’ in VR the expected ‘stability’ of visual anchors. To explore the effect of ‘reality’ we introduced an accommodation-vergence conflict. We show that VEPR are appropriately modulated only when virtual visual ‘anchors’ are rendered such that vergence and accommodation cues are consistent. In a second experiment we directly test whether cognitive Assessment of the likely stability of real Perceptual anchors (we contrast a ‘teapot on a stand’ and a ‘helium balloon’) affects VEPR. We show that the perceived positional stability of environmental anchors modulate postural responses. Our results confirm previous findings showing that postural sway is modulated by the configuration of the environment and further show that an Assessment of the stability and reality of the environment plays an important role in this process. On this basis we propose design guidelines for VR systems, in particular we argue that accommodation-vergence conflicts should be minimised and that high quality motion tracking and rendering are essential for high fidelity VR.

Tiesong Zhao - One of the best experts on this subject based on the ideXlab platform.

  • PEA265: Perceptual Assessment of Video Compression Artifacts
    IEEE Transactions on Circuits and Systems for Video Technology, 2020
    Co-Authors: Liqun Lin, Liping Zhou, Weiling Chen, Tiesong Zhao
    Abstract:

    The most widely used video encoders share a common hybrid coding framework that includes block-based motion estimation/compensation and block-based transform coding. Despite their high coding efficiency, the encoded videos often exhibit visually annoying artifacts, denoted as Perceivable Encoding Artifacts (PEAs), which significantly degrade the visual Quality-of-Experience (QoE) of end users. To monitor and improve visual QoE, it is crucial to develop subjective and objective measures that can identify and quantify various types of PEAs. In this work, we make the first attempt to build a large-scale subject-labeled database composed of H.265/HEVC compressed videos containing various PEAs. The database, namely the PEA265, includes 4 types of spatial PEAs (i.e. blurring, blocking, ringing and color bleeding) and 2 types of temporal PEAs (i.e. flickering and floating). Each containing at least 60,000 image or video patches with positive and negative labels. Based on the PEA265 database, we develop and optimize Convolutional Neural Networks (CNNs) to objectively recognize different types of PEAs. Experiments show that our architecture is capable of identifying the 6 types of PEAs with an accuracy over 86%. To further demonstrate its application, we explore the relationship between collected PEA intensities and subjective quality scores of compressed videos. A quality metric is consequently proposed with superior performance in terms of correlation to Mean Opinion Score (MOS) values. We believe that the PEA265 database and our findings will benefit the future development of video quality Assessment methods and Perceptually motivated video encoders.

Mingshao Tsai - One of the best experts on this subject based on the ideXlab platform.

  • autologous thyroid cartilage graft implantation in medialization laryngoplasty a modified approach for treating unilateral vocal fold paralysis
    Scientific Reports, 2017
    Co-Authors: Mingshao Tsai, Mingyu Yang, Genghe Chang, Yaote Tsai, Menghung Lin, Chengming Hsu
    Abstract:

    Medialization laryngoplasty is the standard surgical treatment for unilateral vocal fold paralysis. This study presents a modified approach in which a thyroid cartilage graft is implanted in medialization laryngoplasty. 22 patients who underwent this approach were included in the study. The results revealed that glottal incompetence and vocal performance were markedly improved following surgery, and the follow-up period ranged from 6 to 74 months (mean, 21.4 months). Acoustic analysis revealed significant improvements in the maximum phonation time (from 3.51 to 7.89 seconds, p < 0.001), F0 (from 221.7 to 171.0 Hertz, p = 0.025), and jitter (from 7.68 to 3.19, p < 0.001). Perceptual Assessment revealed a significant decrease in voice grading (from 2.59 to 1.41, p < 0.001), roughness (from 1.82 to 1.23, p = 0.004), and voice breathiness (from 2.55 to 1.23, p < 0.001). None of the patients exhibited severe wound infection, tissue rejection, or other complications attributed to the surgical procedure. In conclusion, autologous thyroid cartilage implantation in medialization laryngoplasty medializes the vocal cord, minimizes the glottal gap, and improves the voice of patients with vocal fold paralysis. This procedure is characterized by simplicity, safety, and acceptable results.

Fabrizio Ottaviani - One of the best experts on this subject based on the ideXlab platform.

  • vocal improvement after voice therapy in unilateral vocal fold paralysis
    Journal of Voice, 2008
    Co-Authors: Antonio Schindler, Alessandro Bottero, Pasquale Capaccio, Don Ginocchio, Fulvio Adorni, Fabrizio Ottaviani
    Abstract:

    Summary Unilateral vocal fold paralysis (UVFP) is associated with changes in acoustic and aerodynamic voice measurements and can have a significant impact on a patient's quality of life. Few objective data regarding the efficacy of voice therapy for UVFP exist. The aim of this study was to retrospectively analyze voice modifications in a group of patients with UVFP before and after voice therapy. Forty patients with UVFP of different etiology were included in the study. Each subject had voice therapy with an experienced speech/language pathologist twice a week; the mean number of sessions was 12.6. A multidimensional Assessment protocol was used; it included videoendoscopy, the maximum phonation time (MPT), the GIRBAS scale, spectrograms and a perturbation analysis, and the Voice Handicap Index (VHI). Pre- and posttreatment data were compared by means of the Wilcoxon and Student's t tests. A complete glottal closure was seen in 8 patients before voice therapy and in 14 afterward. Mean MPT increased significantly. In the Perceptual Assessment, the difference was significant for five out of six parameters. A significant improvement was found on spectrographic analysis; as for perturbation analysis, the differences in jitter, shimmer, and noise-to-harmonic ratio values were significant. VHI values showed a clear and significant improvement. A significant improvement of voice quality and quality of life after voice therapy is an often reached and reasonable goal in patients with UVFP.

  • vocal improvement after voice therapy in unilateral vocal fold paralysis
    Journal of Voice, 2008
    Co-Authors: Antonio Schindler, Alessandro Bottero, Pasquale Capaccio, Don Ginocchio, Fulvio Adorni, Fabrizio Ottaviani
    Abstract:

    Summary Unilateral vocal fold paralysis (UVFP) is associated with changes in acoustic and aerodynamic voice measurements and can have a significant impact on a patient's quality of life. Few objective data regarding the efficacy of voice therapy for UVFP exist. The aim of this study was to retrospectively analyze voice modifications in a group of patients with UVFP before and after voice therapy. Forty patients with UVFP of different etiology were included in the study. Each subject had voice therapy with an experienced speech/language pathologist twice a week; the mean number of sessions was 12.6. A multidimensional Assessment protocol was used; it included videoendoscopy, the maximum phonation time (MPT), the GIRBAS scale, spectrograms and a perturbation analysis, and the Voice Handicap Index (VHI). Pre- and posttreatment data were compared by means of the Wilcoxon and Student's t tests. A complete glottal closure was seen in 8 patients before voice therapy and in 14 afterward. Mean MPT increased significantly. In the Perceptual Assessment, the difference was significant for five out of six parameters. A significant improvement was found on spectrographic analysis; as for perturbation analysis, the differences in jitter, shimmer, and noise-to-harmonic ratio values were significant. VHI values showed a clear and significant improvement. A significant improvement of voice quality and quality of life after voice therapy is an often reached and reasonable goal in patients with UVFP.