Speech perception was believed to play an important role in speech production, but there were no direct evidence of such interactions under normal speech conditions. A new method TAF (Transformed Auditory Feedback) has been developed to investigate effects of auditory feedback during phonation. TAF introduces a minimal parametric perturbation which would not disrupt speech but which would allow us to detect possible perception/production interactions, using a correlation analysis of the input perturbation and the output speech parameters. A series of experiments were performed using the fundamental frequency perturbation, and revealed that the produced speech under TAF shows a corrective response to the perturbation with 150ms response latency on average. The proposed method will also provide a non-invasive measurement of auditory processes using one's own voice as a probe.
This paper describes a new method of Sound-image distance-control for 3D TV. with this method, a real sound image can be localized on the distance of the corresponding video image. An audio signal is fed to two-dimensionally arrayed loudspeakers with appropriate time delays so that the sound waves focus a point. The results of subjective evaluation of Sound image distance using an experimental array show that a stable sound image is actually perceived near the focal point.
For the purpose of investigating spontaneous blink intervals, Marvok properties of the stochastic point process were analyzed. Electro-oculography was adopted to measure spontaneous blinks with and without mental task. As the results, subjects with task exhibited weak Markov properties, and subjects without task, strong ones respectively. These results suggest that blinks evoked by stationary physical stimulus such as dryness and dust happen depending on the ealier events, and that blinks evoked by transient cognitive factors happen randomly.
This study proposes a new method to estimate the visual load objectively and briefly. The closing and opening durations of the spontaneous blink were used as physiological indices, which were derived from the initiation and peak points of the electro-oculography waveform. Three experiments were carried out: the changes of the closing and opening durations due to the experimental visual load, due to the biological rhythm, and due to the width of palpebral fissure, were investigated respectively. It became clear that the opening duration of a spontaneous blink prolongs by the visual load, which is not sensitive to the biological rhythm, the interindivisual variations, and the initial width of palpebral fissure.