Norihiro Uemi

Design of a new electrolarynx having a pitch control function

In order to improve a naturalness of an electrolarynx, we have designed a new method that can allow laryngectomees to control voice intonation by using their expiration. First, we investigated the ability of pitch control of 16 laryngectomees. From the results, two of the laryngectomees could control the pitch frequency accurately and the ability of pitch control improved after one weeks training. Next, we have designed a new electrolarynx having a function of pitch control by expiration pressure. From the view point of naturalness of a spoken sentence and the easiness to control the electrolarynx, the optimal transform function was estimated. The pitch pattern of a sentence obtained by the electrolarynx became clearly similar to that produced from a normal subject after short time training.<<ETX>>

Improved Word Perception in Tinnitus Patients Following Electrical Stimulation of the Ear: A Preliminary Report

The present study showed that there were close relationships between tinnitus relief and improved word perception by means of a grammatically correct but non-sense Japanese word perception test. Fourteen out of 20 patients reported tinnitus relief and improvement in hearing. Nine out of the 14 patients were thought to be significantly improved in word perception. Improved word perception was observed in 7 out of 10 patients whose ears tested were opposite to ears treated while in 2 out of 10 patients whose ears tested were the same as ears treated. Improved word perception was observed in 5 patients at one segment, 2 patients at two segments and 2 patients at three segments. Improved word perception was observed in one patient at the first segment, 5 patients at the second segment, 5 patients at the third segment and 5 patients at the fourth segment. There were no significant differences in hearing level nor age in patients with and without relief of tinnitus.

Preliminary Study of Improved Perception of Words with the Same Sound but Different Intonation in Tinnitus Patients Following Electrical Stimulation of the Ear

The present study aimed to explain how tinnitus relief following electrical promontory stimulation affects detection of changes in pitch frequency. To determine the effects of tinnitus relief on the auditory system. Japanese words with the same sound but different intonation were used to verify the effects of tinnitus relief on pitch detection in tinnitus patients Eight out of 11 patients experienced relief of tinnitus following treatment. The averaged number of the ratio in 8 patients with relief of tinnitus, 0.58, was significantly higher (p < 0.02) than that in 3 patients without relief, 0.15. In comparison with averaged hearing level, there was no significant difference in averaged hearing level between 8 patients with relief of tinnitus (52.4 dBSL; SD: 11.4) and 3 without relief of tinnitus (58.0 dBSL; SD: 14.7) (p > 0.68). No significant difference in age between patients with and without relief of tinnitus was observed.

Tone modifications used for improving the discrimination of Mandarin words for the hearing-impaired

In this paper, a digital processing method is described for modifying tone contrast that was defined as the difference in frequencies between peaks and valleys of pitch curves in natural utterances. Speech signals with modified tones were presented to hearing-impaired Chinese listeners who were asked to identify four alternative Mandarin words. Employing this method, it was found that modified speech with enhanced tone contrast contributed moderate gains in the percentage correct word identification when compared to unmodified speech, while reducing tone contrast generally reduced the percentage correct identification. These findings therefore offer support to the assertion that a hearing aid with tone modifications is indeed effective for hearing-impaired Chinese.

Improved Word Perception Following Electrical Stimulation of the Ear in Hearing-impaired Patients Without Tinnitus

Improved word perception in hearing-impaired patients following electrical stimulation of ears was shown by means of a grammatically correct but non-sense Japanese 4-segment sentence perception test. Improved word perception was reported in 15 out of 20 patients without tinnitus following electrical stimulation of ears. In 11 out of 15 patients, the number of incorrect words significantly decreased, showing that electrical stimulation of ears improved word perception. Improved word perception was observed in 5 out of 8 patients whose tested ears were contralateral to treated ears while in 8 out of 12 patients whose tested ears were the same as treated ears. The present study suggests that electrical stimulation of ears improves word perception in hearing-impaired patients without tinnitus.

Electrical stimulation of the cochlea improved word recognition under noises in tinnitus patients

Hearing impaired patients sometimes complain of poor understanding of speech under noise. It was shown that electrical stimulation of the cochlea in tinnitus patients improved their word recognition. The objective of this study is to show that electrical stimulation of the cochlea in tinnitus patients improved their word recognition under noises. Twenty four‐segment sentences mixed with multiple talk recorded on a CD were delivered to tested ears at a comfortable level via a headphone. The signal‐to‐noise ratios were 0‐, 5‐, and 10‐dB. Patients were requested to repeat what they heard. Improved score was calculated at each segment in 20 sentences. A sinusoidal wave of 10 kHz at the intensity of 200 μA was delivered to the cochlea. The stimulating Pt–Ir electrode was placed on the middle ear and the return electrode, which is made of a plate electrode for ECG, was placed on the skin behind the ear. Alternatively, an external electrical stimulation was applied to patients. Improved word recognition was show...

The effect of electrical cochlear stimulation on the autonomic nervous system

Extracochlear electrical stimulation seems to induce relaxation with temporal tinnitus relief in patients. Electrical treatment was accompanied by increased cutaneous blood flow in the digits, although there was no clear tendency among tinnitus suppression, relaxation, and blood flow. To elucidate the effect on the autonomic system in the experimental animals, the blood pressure, the heart rate, and sympathetic and parasympathetic nervous activities were examined in rats and rabbits. Various stimuli such as square pulses, biphasic pulses, or sine waves were given to the cochlea with the electrodes on the round windows. The arterial blood pressures decreased in most cases in rabbits, while they decreased, increased, or represented biphasic changes in rats depending upon the type of stimulation. The autonomic activity seemed to follow the drifts in blood pressure, but the results did not show which autonomic system contributed to the drifts clearly. The effect of electrical stimulation on the autonomic nerv...