Biomedical subjects

R Inaba

Publications and source records attributed to R Inaba.

At least 19 recordsLinked to original sources

PubMed2004

Changes in prostaglandin F concentration in the uterus (shell gland) of the hen oviduct in relation to oviposition and estrogen.

The prostaglandin F (PGF) concentration of the uterus (shell gland) of the hen oviduct, measured by a radioimmunoassay, was found to increase slightly 6 h before oviposition and steeply immediately after oviposition. An intravenous injection of arginine vasotocin (AVT) caused the increase in the uterine PGF concentration and induced oviposition. When indomethacin was injected before the injection of AVT, the uterine PGF concentration was not increased, and the incidence of oviposition was reduced. Estrogen injection caused an increase in the uterine PGF concentration at 1 and 2 h after injection. Specific binding of the estrogen receptor of the uterine tissue increased 9 and 7 h before oviposition. The slight increase in the uterine PGF concentration 6 h before oviposition may be due to the action of estrogen via its receptor, and the steep increase immediately after oviposition may be caused by AVT released at the time of oviposition.

Animals↗

PubMed2001

Regulatory domain of protein stability of human P51/TAP63, a P53 homologue.

The amino terminal of human P51/TAp63, a P53 homologue, possesses a transactivation domain involved in the activation of its target genes by binding to DNA elements responsive to the p53 protein family. Using a series of amino terminal deletions, the transactivation domain was mapped between amino acid residues 50 to 69. This domain also regulates protein stability in a proteasome-dependent manner, and Ser51 and Ser68 were found to be essential for this stability. Our results suggest that P51 activity is greatly affected by protein stability.

Amino Acid Sequence↗

PubMed2001

Auditory threshold reduction on alcohol ingestion.

RATIONALE: Auditory threshold (AT) measurement method has become the standard behavioral procedure for describing auditory sensitivity. Therefore, the AT measurement method is applicable to evaluation of auditory function. However, only a few studies have been performed to clarify the alteration of audibility under the influence of alcohol on normal humans by measurement of AT. OBJECTIVE: The fact that blood alcohol concentration (BAC) is influenced by the dose of alcohol and the time of measurement suggests that the effects of alcohol may also be altered by the same factors. The present study was conducted to elucidate how alcohol ingestion method affects the AT at a wider range from lower to higher frequency in the time course. METHODS: Fifteen paid Japanese (seven men and eight women, 20-33 years of age) were employed in AT measurements at an octave frequency ranging from 250 to 8,000 Hz before and 5, 30, 60, 120, 240 and 480 min after drinking various amounts (125, 250, 500 and 1,500 ml) of normal beer (5% alcohol) or alcohol-free beer. RESULTS: The AT was significantly reduced within 30 min after the ingestion of 250 and 500 ml of beer, occurring on and after peak BAC. The reducing effect disappeared 480 min after ingestion. CONCLUSIONS: Drinking extra small amounts of alcohol induces the reduction of AT. The effect of alcohol on AT is altered by the alcoholic dose used in testing.

Adult↗

PubMed2001

Effects of different durations of exercise on macrophage functions in mice.

The effects of differing durations of daily exercise on macrophage functions in mice were studied. Male ICR mice aged 4 wk were divided into five groups: a nonexercise group (control) and four exercise groups with differing daily exercise durations of 15--120 min (Exr groups). The exercise applied was 5 days/wk treadmill running at 13 m/min for 12 wk. The potentiation of the phagocytosis function of the reticuloendothelial system and the glucose consumption of peritoneal macrophages in the Exr 30, 60, and 120 groups were significantly higher than those in the control group. Superoxide anion production of peritoneal macrophages in both the absence and the presence of phorbol 12-myristate 13-acetate in the Exr 60 and 120 groups was significantly higher than that in the control group. The acid phosphatase and beta-glucuronidase activities of peritoneal macrophages in the Exr 30, 60, and 120 groups were significantly increased. These results suggest that treadmill running exercise for at least 30 min/day (30--120 min) effectively enhances macrophage functions in mice. These data provide preliminary evidence indicating that chronic exercise-induced increases in phagocytic activity exhibit a dose-dependent relationship with exercise duration.

Acid Phosphatase↗

PubMed2000

Immunomodulation by 8-week voluntary exercise in mice.

This study was designed to evaluate the effects of voluntary exercise on macrophage and lymphocyte functions in mice. Male A/He inbred mice aged 19 weeks were divided into two groups: a group given voluntary exercise and a control group (n = 10 in each group). Exercise consisted of spontaneous running in wheels for 8 weeks (3 days week-1). Glucose consumption of peritoneal macrophages in the exercise group during incubation up to 72 h was significantly higher than that in the control group (70 and 13%, respectively). Also, activities of acid phosphatase (APH) (10.75 +/- 0.37 IU), beta-glucuronidase (GLU) (1.55 +/- 0.07 IU) and lactate dehydrogenase (LDH) (43.3 +/- 0.7 IU) in the peritoneal macrophages in the exercise group was significantly increased (P < 0.01). Compared with the control group, the exercise group had a significant increase of about twofold in macrophage production of nitric oxide (NO2-) stimulated by lipopolysaccharide (LPS) (11.1 +/- 0.1 vs. 5.9 +/- 0.1 microM mL-1 in exercise and control groups, respectively; P < 0.01). Stimulation indices both by concanavalin A (Con A) and phytohaemagglutinin were also significantly higher in the exercise group (P < 0.01). A significant increase in the splenocyte production of interleukin-2 (IL-2) stimulated by Con A was noticed in the exercise group (354.1 +/- 28.8 vs. 218.9 +/- 23.5 pg mL-1 in exercise and control groups, respectively; P < 0.01). These findings suggest that voluntary exercise enhances not only macrophage function but also lymphocyte responsiveness in mice. In the studies of voluntary exercise, evaluation of NO2- production, as an indicator of macrophage function, is recommended.

Acid Phosphatase↗

PubMed2000

[A 5 year follow-up study on the relationship between changes in serum lipids and blood pressure, and changes in exercise habits in subjects 30 years of age].

A 5 year follow-up study was conducted to investigate the relationships between %changes in serum lipids and blood pressure and corresponding changes in exercise habits in the middle-aged. The subjects were 152 males and 169 females who received a health check-up at 30-years-old during the period between 1990-1992 and then at 35-years-old during the period between 1995-1997. The results are as follows: 1. In multiple regression analysis, % delta toriglyceroid (TG) and % delta AI(atherogenic index) ratio were associated significantly with changes in exercise habits in males (P < 0.05) and % delta high density lipoprotein cholesterol (HDLC) was associated with changes in exercise habits in females (P < 0.05). % delta TG and % delta HDLC were affected by changes in exercise habits adjusted for BMI, smoking, and drinking. But changes in TC and blood pressure were not affected by changes in exercise habits. 2. In males, % delta TG was significantly lower in those subjects who started their exercise habit than in the no exercise group and than in those within the ceased exercise group who ceased their exercise during the study period (P < 0.05). % delta AI was significantly lower in the started exercise group than in the no exercise group. Also, the continued exercise group had a significantly (P < 0.05) lower % delta AI as compared to the ceased exercise group. In females, % delta TG was significantly lower in the started exercise group than in the no exercise group (P < 0.05). % delta HDLC was higher significantly in the continued exercise group than in the ceased exercise group (P < 0.05). From the results obtained, it is recommended that the no exercise subjects should have exercise more than once time per week and those with more than 1 time per week maintain their exercise habits.

Adult↗

PubMed1999

Immunomodulatory action of citrus auraptene on macrophage functions and cytokine production of lymphocytes in female BALB/c mice.

The modifying effects of auraptene isolated from the peel of citrus fruit (Citrus natsudaidai Hayata) on macrophage and lymphocyte functions were investigated in mice. Female BALB/c mice were gavaged with auraptene at a dose of 100, 200 or 400 mg/kg once a day for 10 consecutive days. Glucose consumption of peritoneal macrophages was significantly higher than that in the control group (P < 0.05-0.001) in auraptene-treated mice at all doses at 24, 48 and 72 h incubation except for mice given 200 mg/kg auraptene at 24 h incubation. Activity of acid phosphatase in peritoneal macrophages was significantly increased in mice treated with auraptene at a dose level of 100 mg/kg (P < 0.001). Activity of beta-glucuronidase in peritoneal macrophages in the auraptene-treated mice at all doses was significantly higher than that in the control group (P < 0.001), but there was no significant difference in lactate dehydrogenase activity of peritoneal macrophages at any dose. Interleukin (IL)-1beta production of peritoneal macrophages in the auraptene-treated mice at all doses was significantly higher than that in the control group (P < 0.05-0.001). Tumor necrosis factor alpha production of peritoneal macrophages in mice gavaged with auraptene at a dose of 200 mg/kg was significantly higher than that in the control group (P < 0.05). Auraptene did not affect proliferation of spontaneous splenic lymphocytes in mice at any dose. Stimulation indices in mice given auraptene at a dose of 200 mg/kg were significantly higher than that in the control group (P < 0.05). When spleenic lymphocytes were cultured without concanavalin A (Con A), IL-2 and interferon (IFN) gamma productions were not detectable in the supernatant. However, IL-2 and IFN production stimulated by Con A were significantly increased in mice gavaged with auraptene at dose levels of 100 and 200 mg/kg (P 0.05-0.001). Auraptene did not enhance spontaneous IL-4 production by splenocytes. There was no significant difference in IL-4 production of splenic lymphocytes stimulated by Con A in all groups. These findings might suggest that oral administration of citrus auraptene effectively enhanced macrophage and lymphocyte functions in mice.

Acid Phosphatase↗

PubMed1999

[Mental health and stress coping among hospital nurses by stress & stress-coping questionnaire].

This study was aimed to evaluate the relationship between the mental health level and stress coping style in a group of female subjects in a public hospital. A self-administrated questionnaire including questions on nursing work, the General Health Questionnaire (GHQ) as well as the Stress and Stress Coping questionnaire (SSCQ) was used. The subjects of this study were 225 female nurses. The subjects' age and working experience (mean +/- SD) were 34.0 +/- 10.3 and 10.6 +/- 8.3 years, respectively. The results obtained were as follows: 1) Either of the following determinants was related to negative mental health: experience of 1-2 years; working in the operating room or in-patient department. 2) The subjects whose working experience was < 5 years or > or = 10 years had higher scores in the SSCQ. These subjects were among those who did not have higher scores in the GHQ. It was suggested that these subjects need to receive a guidance in stress coping. These findings suggest that because working conditions have a negative influence on mental health, educational system for both inexperienced and experienced nurses is needed to develop an effective stress-coping style in medical institutions.

Adaptation, Psychological↗

PubMed1999

A four-year follow-up study on subjective symptoms and functional capacities in workers using hand-held grinders.

Fifty-three grinders in the metal industry were re-examined 4 years after their first examination. Information about age, occupation, daily vibration exposure, drinking and smoking habits, and presence of subjective symptoms such as vibration-induced white finger (VWF), and numbness and pain in the fingers was collected during the first and second examination. Cold provocation test (10 degrees C/10 min) was also employed to evaluate disturbances in the peripheral circulatory and peripheral nerves in all subjects. The frequency-weighted vibration acceleration of various types of hand-held tools was measured. There was no subject with VWF at the first examination; however, during the course of follow-up, two cases (3.8%) of VWF with latent interval of more than 25 years were diagnosed. Prevalence of numbness in the fingers and shoulder stiffness was significantly higher at the second examination. When the prevalence of subjective symptoms was tested by the subjects' total operating time (TOT) during the 4-year follow-up period, those whose TOT was equal to or more than 2500 hours showed higher prevalence compared to the other subgroup. The paired values of recovery rate of finger skin temperature and vibration sensation threshold after the cold water immersion test were significantly different at the first and second examination. On average, the diminution of hand-grip force during the 4-year follow-up course was 7.4%; the difference being significant at 0.01 level. Significant differences in the paired data of pinching power and tapping ability could be detected. The frequency-weighted vibration acceleration of various tools was in the range of 1.1-4.6 m/s2. It was concluded that: (1) prolonged occupational exposure to the vibration of hand-held grinding tools should be considered as a risk factor causing disturbances in the hand-arm system of the operators; (2) the results of recovery rate of finger skin temperature and the vibration sensation threshold seemed to be appropriate indicators for the assessment of peripheral vascular and peripheral nerve disturbances in workers exposed to hand-arm vibration; and (3) to reduce the subjects' physical stress, attention should be paid to ergonomic factors.

Adult↗

PubMed1999

Increase of the cellular growth of old human diploid fibroblasts by radical scavenger: methanolic extract of broad beans.

The methanolic extract from broad beans (MEBB), which is comprised of phenolic compounds, has free-radical scavenging activity. The effects of MEBB on cytosolic antioxidant enzymes and cell proliferation were examined in cultures of old (78-84% life-span completed) WI-38 human diploid fibroblasts. Because catechin is polyphenol and has radical scavenging activity, it was used as the control in experiments. We observed that MEBB increased cellular growth when added to the cell culture. In MEBB at 40 and 120 micrograms/mL, the cell proliferation increased by 14 and 27%, respectively, as compared to the control. In catechin, cell proliferation increased as well. Regarding cytosolic glutathione peroxidase (GSH-Px) activity, treatment of old cells with MEBB at 40 and 120 micrograms/mL resulted in decreases as compared to the control. In contrast, catechin showed no similarities to the modification of GSH-Px activity. Cytosolic SOD activity was increased by treatment with 40 micrograms/mL MEBB, and the activity showed a gradual decrease with increased MEBB concentrations. A similar trend occurred in the cells treated with catechin (4-20 microM). These results suggest that cytosolic antioxidant enzyme activities in old cells may be modulated by MEBB treatment. We conclude that there may be a relation between the optimum MEBB concentration for the increase of cellular growth and the MEBB concentration required to exhibit a decrease in GSH-Px activity.

Antioxidants↗

PubMed1998

[An evaluation of the biting force, the body composition and the amount of masticatory action in young females].

UNLABELLED: The purposes of this study were to investigate factors related to maximum biting force and to understand the characteristics of physical properties of daily ingested foods in young females. One hundred and forty subjects aged 18-23, with Angle 1 class occlusion, had not suffered from periodontitis, and had not been treated for preparation of tooth crown of first molars. Body height and weight were measured, and percentage of body fat, fat mass (FM) and lean body mass (LBM) were estimated, using the impedance analyzer. The maximum biting force was measured by the press sensation method. According to the formula on the basis of our new version of Yanagisawa's food classification, the mean value of the amount of masticatory action for one day was calculated. Subjects were divided into the normal biting force and the low biting force groups with -1SD of the maximum biting force, in order to compare body composition and backgrounds in sports activities between these two groups. Multiple linear regression analysis was carried out, employing maximum biting force (kg.f) as a dependent variable, and having a background in sports activities, FM, LBM, the number of missing teeth, the number of dental caries and the amount of masticatory action for one day as independent variables. Results were as in the following: 1) The proportion of subjects who had a background in sports activities in the low biting force group were less than that in the normal biting force group (p < 0.01). 2) Having a background in sports activities and LBM were positively correlated to maximum biting force (p < 0.01), while the amount of masticatory action for one day was not. 3) All subjects, especially those in the low biting force group seldom had food requiring the highest amount of masticatory action. CONCLUSION: Having a background in sports activities and LBM are positively correlated with the maximum biting force, while the amount of masticatory action for one day was not correlated positively nor negatively in young females.

Adolescent↗

PubMed1998

[The presentation level of interrupted pure tone for inducing the pulse phenomenon of continuous white noise].

When two sounds which have same spectrum but different amplitude are alternated without silent gap between the sounds, the lower amplitude sound comes to be heard as continuous. This is called "auditory induction" which is one of the most interesting auditory phenomena. The fainter sound is called induce and the louder sound is called inducer. The authors previously reported that the addition of interrupted pure tone to continuous white noise induced the pulsed noise. This pulse phenomenon was thought to be a kind of auditory induction; the inducer is the noise image of white noise with the silent part of interrupted pure tone and the induce is the noise image of white noise with the pure tone part of interrupted pure tone. The authors hypothesized that an auditory filter made with the pure tone of interrupted pure tone generates the two noise images in the continuous white noise. Present experiments were made to investigate the change of "the threshold of interrupted pure tone for inducing the pulse phenomenon" (TIP) when the presentation level of continuous white noise and the frequency of interrupted pure tone are changed. TIP was constant and independent of both the amplitude of continuous white noise and the frequency of interrupted pure tone. All subjects reported that the higher the frequency of interrupted pure tone is, the harder it becomes to hear the pulsed noise image. It is supposed that this phenomenon does not contradict the theory of the auditory filter.

Acoustic Stimulation↗

PubMed1998

Finger skin temperature and laser-Doppler finger blood flow in subjects exposed to hand-arm vibration.

OBJECTIVES: This study was aimed to assess the peripheral circulatory functions of forestry workers exposed to hand-arm vibration, using simultaneous measurements of finger skin temperature (FST) and finger blood flow (FBF). METHODS: The subjects were five men with vibration-induced white finger (VWF), four subjects with numbness in their hands and five exposed controls without any signs or symptoms related to vibration syndrome. Simultaneous measurements of FST and laser-Doppler FBF were performed before, during and following a 10-min recovery period after the hand was immersed in cold water (10 degrees C, 10 min). Partitional measurements of finger blood flows could be made between the capillaries and deeply located vessels using two laser-Doppler flow probes having narrower and wider optic fiber separations. RESULTS: The FST as well as the FBF of the capillary and deeply located vessels during and following the cold immersion test in those with VWF and in the subjects with numbness had a slight increase immediately following the cold immersion and no tendency to be augmented as the time span increased. After the cold immersion test, the control group had significantly greater FST and FBF compared to other groups. Particularly, from the 5th to the 10th min after the cold provocation, the values of FBF of the deeply located vessels in those with VWF were significantly lower than the controls. During the course of observation, the FST had significantly linear relationship with the recorded capillary and deep FBF values, and that was much closely correlated with the deep FBF (i.e., P < 0.01 in each selected condition). The slope of the regression lines in the capillary were steeper and shallow in the deep FBF. CONCLUSIONS: In addition to the measurement of capillary FBF, more detailed and accurate information on the peripheral circulatory functions of vibration-exposed subjects can be obtained by including the assessment of the deep FBF.

Aged↗

PubMed1998

[Environmental factors possibly associated with onset of senile dementia].

Factors associated with senile dementia have not been clarified, and factors, especially those in the living environment which seem to have a close link to the dementia need to be analysed. We conducted a case-control study targeting patients within the jurisdiction of Nagahama Public Health Center in Shiga and Hikone city, who are diagnosed to have senile dementia of the Vascular type, senile dementia of the Alzheimer type, and senile dementia of the Mixed type, and compared them to age matched controls. The outcome of the study by Matched pair analysis (McNemar's test) before the onset of the senile dementia were as follows. 1 The factors related to senile dementia of the vascular type were: Previous histories (Matched Odds Ratio (MOR): 8.0 p < 0.05), disturbance of the lower limbs (MOR = 8.0 p < 0.05). Environmental factors were: strong preference for sweets (MOR = 8.0 p < 0.05 female), smoking (MOR = 3.7 p < 0.10), lower utilization of health care (MOR = 3.3 p < 0.10), such as periodic medical check (MOR = 0/6 p < 0.10), sleep (MOR = 0/5 p < 0.10), less commitment to hobbies (MOR = 2.6 p < 0.10), such as handicrafts (MOR = 0/5 p < 0.10) etc, less intercourse with relatives (MOR = 0/9 p < 0.01), not living together with children's family (MOR = 0.20 p < 0.05 female), and death (MOR = 8/0 p < 0.05) or hospitalization (MOR = 9.0 p < 0.05) of a family member. 2 The factors related to senile dementia of the Alzheimer type and the Mixed type were: some previous histories (MOR = 8.0 p < 0.05), less disturbance of gait (MOR = 0/5 p < 0.10). Environmental factors were: lower utilization of health care, such as periodic medical check (MOR = 0.18 p < 0.05), and lower participation in exercise (MOR = 0/5 p < 0.10) etc, less association with neighbors (MOR = 0.11 p < 0.05), less participation in community activities (MOR = 0.11 p < 0.05), not living together with children's family (MOR = 0/8 p < 0.05), relocation (MOR = 5/0 p < 0.10) and retirement (MOR = 5/0 p < 0.10).

Aged↗

PubMed1997

Assessment of hand-arm vibration exposure among traffic police motorcyclists.

The aims of this study were (1) to evaluate subjective symptoms in the hand-arm system of all traffic police motorcyclists of a city located in the central part of Japan and (2) to assess their hand-arm vibration exposure associated with traffic police motorcycle riding. The study population consisted of 119 motorcycling traffic policemen and 49 male controls. By means of a questionnaire, information on the occupational history and the presence of subjective symptoms in the hand-arm system of all subjects was obtained. Vibration was measured on the handlebars of the representative motorcycles and on the hands of the riders. The 4- and 8-h energy-equivalent frequency-weighted acceleration as well as the lifetime vibration dose were calculated for all police motorcyclists. The prevalence of finger blanching in the traffic police motorcyclists was 4.2%, but none of the controls had this symptom. The rates of finger numbness (19.3%), finger stiffness (16.0%), shoulder pain (13.4%), and shoulder stiffness (45.4%) were significantly higher among police motorcyclists as compared with controls. The root-mean-square (rms) frequency-weighted acceleration on the handlebars of police motorcycles was in the range of 2.2-4.9 m/s2 rms. The computed 4- and 8-h energy-equivalent frequency-weighted acceleration values were 2.8-4.5 and 2.0-3.2 m/s2 rms, respectively. A pattern of increasing percentage prevalence with increasing cumulative vibration dose was noticed. The subjects with a lifetime vibration dose of more than 20.1 m2 h3 s-4 (in scale) showed significantly higher prevalence rates for symptoms in the fingers and shoulders as compared with the control group. As occupational vibration exposure of traffic police motorcyclists might be considered a risk factor for the development of symptoms in the hand-arm system of the riders, its evaluation and control is needed for prevention methodology evolution.

Adult↗

PubMed1997

[Effects of voluntary exercise on nonspecific immunological mechanisms in mice].

We studied the effects of voluntary exercise on nonspecific immunological mechanisms in mice. In this study, 7 week old male ICR mice were divided into two groups: a non-exercise group (control) and a group given voluntary exercise (Vex group). Each mouse of the Vex group was kept in an individual cage equipped with a voluntarily revolving wheel that the mouse had free access to. The duration of voluntary exercise was 3 days per week for 8 weeks. The following results were obtained: 1) After 8 weeks of voluntary exercise, food consumption, the weight of the anterior tibialis muscle and succinate dehydrogenase activity in the anterior tibialis muscle increased significantly in the Vex group compared to the control group. 2) By means of the carbon clearance method, phagocytosis of the reticuloendothelial system was increased in the Vex group. 3) Glucose consumption capacity and O-2 production capacity of peritoneal macrophages (M phi) were significantly increased in the Vex group compared to the control group. 4) The acid phosphatase (APH), beta-glucuronidase (GLU) and lactate dehydrogenase (LDH) activities of peritoneal M phi increased significantly in the Vex group. 5) Concanavalin A (Con A)-induced cell proliferation in the spleen was high in the Vex group. Based on the above findings, it may be surmised that voluntary exercise enhances nonspecific immunological mechanisms and thereby improves the host defense mechanisms in mice.

Animals↗

PubMed1997

[Relationships between maximal oxygen uptake (VO2max) and physical activity, blood pressure and serum lipids].

This study was conducted to investigate the relationships between maximal oxygen uptake (VO2max) and physical activity (occupational and leisure time), blood pressure, and serum lipids. The subjects of this study (n = 727) were those who participated in a "health check for 30-year-olds" in the city of Gifu, Japan, during the period from April 1991 to March 1993. Individuals with a medical history and/or undergoing treatment for coronary heart disease (CHD), other heart diseases, hypertension, diabetes mellitus, liver disease, or renal disease were excluded. Finally, 411 males (30 yrs of age) were considered for this study. VO2max was estimated according to the method of Astrand & Rhyming. The results can be summarized as follows: 1. Both occupational and leisure time physical activity were independently related to VO2max. In subjects with light and moderate occupational physical activity, VO2max was affected by leisure time physical activity rather than occupational physical activity, and in those with heavy occupational physical activity, it was affected by both occupational and leisure time physical activity. 2. According to the results of multiple regression analysis, VO2max adjusted for body mass index, smoking, and alcohol was associated significantly with systolic blood pressure (P < 0.0001), high density lipoprotein cholesterol (HDLC) (P < 0.0001), triglyceride (P < 0.0001), and the (total cholesterol-HDLC)/HDLC ratio (P < 0.0001). From the results obtained it may be concluded that VO2max can be considered as a factor to decrease the risk of CHD.

Adult↗

PubMed1997

[Pulse phenomenon of continuous white noise with interrupted pure tone].

The researches of masking made it clear that there is a bandpass like a filter in the auditory system. This is called the auditory filter and its central frequency is thought to be the frequency of an acoustic signal. If there exist this kind of filter, the authors expected that the noise image which is perceived when pure tone and noise simultaneously presented is different from the one which is perceived when noise is presented independently. The authors chose an interrupted pure tone as an acoustic signal and continuous white noise as noise, and experimented to investigate the pure tone effect on perception of white noise. As a result, two stimulus tones induced three sound images, which are sound images of continuous noise, a pure tone and pulsed noise. The sound image which listeners did not expect to hear was the pulsed noise image. This phenomenon was thought to be an auditory induction; the inducer is the sound image of the white noise presented with the silent part of pure tone of interrupted pure tone and the inducee is that of the white noise presented with pure tone part of interrupted pure tone. This pulse phenomenon suggests that pure tone change the loudness of white noise. This finding is interesting for researches of auditory mechanism and for the field of hygienics with protecting the auditory system and improving hearing under the noisy environment.

Acoustic Stimulation↗