Publications by authors named "Kazuo Ueda"

Our previous investigation on the effect of stretching spectrotemporally degraded and temporally interrupted speech stimuli showed remarkable intelligibility gains [Udea, Takeichi, and Wakamiya (2022). J. Acoust.

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It has been shown that the intelligibility of checkerboard speech stimuli, in which speech signals were periodically interrupted in time and frequency, drastically varied according to the combination of the number of frequency bands (2-20) and segment duration (20-320 ms). However, the effects of the number of frequency bands between 4 and 20 and the frequency division parameters on intelligibility have been largely unknown. Here, we show that speech intelligibility was lowest in four-band checkerboard speech stimuli, except for the 320-ms segment duration.

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The intelligibility of interrupted speech stimuli has been known to be almost perfect when segment duration is shorter than 80 ms, which means that the interrupted segments are perceptually organized into a coherent stream under this condition. However, why listeners can successfully group the interrupted segments into a coherent stream has been largely unknown. Here, we show that the intelligibility for mosaic speech in which original speech was segmented in frequency and time and noise-vocoded with the average power in each unit was largely reduced by periodical interruption.

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The present investigation focused on how temporal degradation affected intelligibility in two types of languages, i.e., a tonal language (Mandarin Chinese) and a non-tonal language (Japanese).

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The intelligibility of interrupted speech (interrupted over time) and checkerboard speech (interrupted over time-by-frequency), both of which retained a half of the original speech, was examined. The intelligibility of interrupted speech stimuli decreased as segment duration increased. 20-band checkerboard speech stimuli brought nearly 100% intelligibility irrespective of segment duration, whereas, with 2 and 4 frequency bands, a trough of 35%-40% appeared at the 160-ms segment duration.

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In the field of psychology, the merge of decision-theory and neuroscientific methods produces an array of scientifically recognized paradigms. For example, by exploring consumer's eye-movement behavior, researchers aim to deepen the understanding of how patterns of retinal activation are being meaningfully transformed into visual experiences and connected with specific reactions (e.g.

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Intelligibility of four-band speech stimuli was investigated (n = 18), such that only one of the frequency bands was preserved, whereas other bands were locally time-reversed (segment duration: 75-300 ms), or vice versa. Intelligibility was best retained (82% at 75 ms) when the second lowest band (540-1700 Hz) was preserved. When the same band was degraded, the largest drop (10% at 300 ms) occurred.

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Intelligibility of temporally degraded speech was investigated with locally time-reversed speech (LTR) and its interrupted version (ILTR). Control stimuli comprising interrupted speech (I) were also included. Speech stimuli consisted of 200 Japanese meaningful sentences.

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Background: Enzyme replacement therapy in Fabry disease has been available in Japan since 2004. Two post-authorization safety studies were conducted to evaluate agalsidase beta in Japanese patients with Fabry disease in real-world practice.

Research Design And Methods: The Special Drug Use Investigation monitored the long-term safety and efficacy of agalsidase beta, and the Drug Use Investigation monitored safety in patients not participating in the Special Drug Use Investigation.

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Experiments that focus on how humans perceive temporal, spatial or synaesthetic congruency in audiovisual sensory information have often employed stimuli consisting of a Gabor patch and an amplitude (AM) or frequency (FM)-modulated sound. Introducing similarity between the static and dynamic features of the Gabor patch and the (carrier) frequency or modulation frequency of the sound is often assumed to be effective enough to induce congruency. However, comparative empirical data on perceived congruency of various stimulus parameters are not readily available, and in particular with respect to sound modulation, it is still not clear which type (AM or FM) induces perceived congruency best in tandem with various patch parameters.

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Aim: Although eye-tracking technology expands beyond capturing eye data just for the sole purpose of ensuring participants maintain their gaze at the presented fixation cross, gaze technology remains of less importance in clinical research. Recently, impairments in visual information encoding processes indexed by novel gaze metrics have been frequently reported in patients with schizophrenia. This work undertakes a scoping review of research on saccadic dysfunctions and exploratory eye movement deficits among patients with schizophrenia.

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The intelligibility of chimeric locally time-reversed speech was investigated. Both (1) the boundary frequency between the temporally degraded band and the non-degraded band and (2) the segment duration were varied. Japanese mora accuracy decreased if the width of the degraded band or the segment duration increased.

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Objectives: Enzyme replacement therapy with idursulfase has been shown to improve somatic signs and symptoms of mucopolysaccharidosis type II (MPS II). Idursulfase is available in Japan (since 2007), based on the outcome of clinical trials conducted in the United States, but data from Japanese patients are limited.

Methods: This was a postmarketing study of Japanese MPS II patients treated with 0.

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Introduction: Alglucosidase alfa received marketing approval for the treatment of Pompe disease in Japan in 2007. We conducted a post-marketing surveillance study to monitor the long-term safety and efficacy of alglucosidase alfa therapy among Japanese patients with Pompe disease.

Methods: The safety and efficacy outcomes were collected as real-world data for up to 9 years following the initiation of treatment with alglucosidase alfa, without any intervention to treatment strategies.

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Irrelevant speech is known to interfere with short-term memory of visually presented items. Here, this irrelevant speech effect was studied with a factorial combination of three variables: the participants' native language, the language the irrelevant speech was derived from, and the playback direction of the irrelevant speech. We used locally time-reversed speech as well to disentangle the contributions of local and global integrity.

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We examined the frequency specificity of amplitude envelope patterns in 4 frequency bands, which universally appeared through factor analyses applied to power fluctuations of critical-band filtered speech sounds in 8 different languages/dialects [Ueda and Nakajima (2017). Sci. Rep.

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Temporal resolution needed for Japanese speech communication was measured. A new experimental paradigm that can reflect the spectro-temporal resolution necessary for healthy listeners to perceive speech is introduced. As a first step, we report listeners' intelligibility scores of Japanese speech with a systematically degraded temporal resolution, so-called "mosaic speech": speech mosaicized in the coordinates of time and frequency.

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A set of experiments was performed to make a cross-language comparison of intelligibility of locally time-reversed speech, employing a total of 117 native listeners of English, German, Japanese, and Mandarin Chinese. The experiments enabled to examine whether the languages of three types of timing-stress-, syllable-, and mora-timed languages-exhibit different trends in intelligibility, depending on the duration of the segments that were temporally reversed. The results showed a strikingly similar trend across languages, especially when the time axis of segment duration was normalised with respect to the deviation of a talker's speech rate from the average in each language.

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Acoustic analyses of eight different languages/dialects had revealed a language universal: Three spectral factors consistently appeared in analyses of power fluctuations of spoken sentences divided by critical-band filters into narrow frequency bands. Examining linguistic implications of these factors seems important to understand how speech sounds carry linguistic information. Here we show the three general categories of the English phonemes, i.

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The peripheral auditory system functions like a frequency analyser, often modelled as a bank of non-overlapping band-pass filters called critical bands; 20 bands are necessary for simulating frequency resolution of the ear within an ordinary frequency range of speech (up to 7,000 Hz). A far smaller number of filters seemed sufficient, however, to re-synthesise intelligible speech sentences with power fluctuations of the speech signals passing through them; nevertheless, the number and frequency ranges of the frequency bands for efficient speech communication are yet unknown. We derived four common frequency bands-covering approximately 50-540, 540-1,700, 1,700-3,300, and above 3,300 Hz-from factor analyses of spectral fluctuations in eight different spoken languages/dialects.

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Factor analysis (principal component analysis followed by varimax rotation) had shown that 3 common factors appear across 20 critical-band power fluctuations derived from spoken sentences of eight different languages [Ueda et al. (2010). Fechner Day 2010, Padua].

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