ИССЛЕДОВАНИЕ УРОВНЯ СЛУХА У РАЗНОВОЗРАСТНЫХ ГРУПП ЛЮДЕЙ

Background: to research the level of hearing sensitivity among people of different age groups with normal hearing ability or with hearing impairment. Methods: the results of hearing test of people of different age groups and those of sociological survey are presented here. Result: 66% of examined have no anomalies of hearing ability, 16% of examined showed results, ranging from 75 to 85 percent of normal, hearing level of 18% of examined is ranged from 60 to 70 percent of normal. Conclusion: hearing impairment is caused by enhanced level of sound pressure, loss of hearing acuity is caused by ageing.

Mathematical Modeling of the Vortex Shedding Structure and Sound Pressure Level of a Large Wind Turbine Tower

The level of noise emission of a circular cylinder, especially a tower of a wind turbine, is remarkably dependent on vortex shedding behind the body of the tower. For these configurations, the key element to reduce noise emission is the upstream flow control of the body. In this paper, the sound pressure level of a wind turbine tower was investigated numerically. In this regard, an in-house OpenFoam solver with Curle’s acoustic analogy was used, and the results were compared with available experimental data, showing proper consistency among them. Then, three passive control methods such as longitudinal slot, splitter plate, and helical strake were applied to control the Kármán vortex shedding behind the tower, followed by the reduction in the level of sound pressure. The results showed that all the above control methods play an essential role in diminishing the fluctuation forces and affect the frequency of vortex shedding. However, the helical strake can lead to the significant suppression of Kármán vortex shedding due to the delay of boundary layer flow separation. Based on the observations, the tower with helical strake reduced the overall level of sound pressure as well as the Aeolian tones in a specific Strouhal number range.

An innovative technology of an athlete’s organism functional reserves increase based on bioacoustical stimulation of the respiratory system

In order to increase an athlete’s organism functional reserves we created the innovative technology based on low-frequency vibrations influence on respiratory system. First we measured acoustic impedance of an athlete’s organism for three phases of respiration at polyharmonic acoustic signal within the range of frequency from 3 Hz to 51 Hz. After that during 2 weeks we organized six sessions of bioacoustical stimulation among the group of 20 athletes, divided into subgroups with an effective (130 dB) and placebo (60 dB) effect. It was stated that six-fold effect of a scanning tonal signal with the level of sound pressure 130 dB within the range 22-36 Hz led to resonance frequency of respiratory system increase, respiratory system sound vibrations imbibitio coefficient decrease and its resistance to sound wave increase because of reserve alveoli opening and the increase of area of cross section of alveolar ways and respiratory bronchial tubes.

Analisis Reverberation Time Terhadap Kenyamanan Audial pada Ruang Auditorium Menara Pinisi UNM

Auditorium space is one of the building functions that must be supported will be acoustic comfort. This research aimed (1) to determine the condition of auditory comfort in the auditorium space according to the opinion of the space users; (2) to investigate the value of the existing reverberation time in the space. The research used two methods, namely the qualitative and quantitative methods; the qualitative method was conducted by distributing questionnaires, interviews and direct observation in the field. The results of the questionnaires were analyzed using SPSS version 22, while the quantitative method was conducted by measuring the sound pressure level using the Sound Level Meter (SLM) and calculation of the Reverbertion Time (RT) by using the Sabine Equation and the simulation was conducted using the Ecotect Software. The research results indicated that, based on the questionnaires distribution to the space user, and according to the seat position, 44.3% of the older users felt comfortable about the spread of sound in the space, while 41.3% did not feel comfortable with the position of the seats and the sound they received, and only 2.0% felt very comfortable with the distribution spread of sound in the space. Meanwhile, the results of the measurement of the highest Level of Sound Pressure showed that at the measuring point of 31 was 94.0 dB and the lowest at point of 22 was 60.8 dB. The results of the RT calculation at the auditorium when the auditorium was empty was about 0.45-0.40 seconds at the frequency of 500hz.

Influence of Contextual Factors on Soundscape in Urban Open Spaces

The acoustic environment in urban open spaces has played a key role for users. This study analyzed the different effects of contextual factors, including shop openness, season, and commercial function, on the soundscape in two typical commercial pedestrian streets. The following observations were based on a series of measurements, including crowd measurements, acoustic environment measurements, and a questionnaire survey. First, the number of talkers in Central Avenue was greater than the number of talkers in Kuan Alley in cases with the same crowd density, while there was no significant difference in the sound pressure level. When the crowd density increased, acoustic comfort trended downward in Kuan Alley, while the value of acoustic comfort in Central Avenue took a parabolic shape. Second, there was no significant difference between the number of talkers in summer and the number of talkers in winter; however, when crowd density increased by 0.1 persons/m2, the level of sound pressure increased by 1.3 dBA in winter and 2.2 dBA in summer. Acoustic comfort took a parabolic shape that first increased and then decreased in both winter and summer. Regarding commercial function, as the crowd density increased, the number of talkers and the level of sound pressure both increased, while acoustic comfort decreased in three zones with different commercial functions. In addition, a cross-tab analysis was used to discuss the relationship between the number of talkers and the level of sound pressure, and it was found to be positive.

Treatment of 40 kHz continuous ultrasound towards blood cells of mice (Mus musculus L)

The application of ultrasound in mice has increased the activity of mice and showed anxious behavior that affects the blood cells of mice. This study aims to observe the effect of 40 kHz ultrasound exposure on the content of leukocytes and erythrocytes in blood cells of mice. For this purpose, five ultrasound treatments with sound pressure levels were 70, 75, 80, 85, and 90 dB respectively and one control in six sample groups, each consisting of five mice with the same weight and age. Sound treatment is carried out with a 40 kHz continuous ultrasound exposure of the same duration for two hours. Taking blood samples of mice is carried out as soon as the sample is given a sound treatment. Based on the results of blood tests of mice it was found that the average increase in the number of leukocyte mice varied between 40-1,070 cells/mm3 for variations in sound pressure levels from 70 to 90 dB with an increase in the highest average number of leukocyte (1,070 cells/mm3) at the sound pressure level 75 dB. With the same level of sound pressure level, the decrease in the average number of erythrocytes varied between 920,000-190,000 cells/mm3 with a decrease in the highest average number of erythrocytes (920,000 cells/mm3) at an 80 dB sound pressure level. The optimum level of sound pressure that can affect the average number of leukocytes and erythrocytes in blood cells of mice are still unknown.

Sound production shows robust loudness constancy when visual cues of musical performance are available

We examined the degree of loudness constancy using two methods of adjustment. One was “sound production,” by which listeners played a musical instrument as loudly as a model player. The other was “sound level adjustment,” by which listeners adjusted the loudness of the sound produced by a loudspeaker. The target sound was produced by the actual musical instrument performance. Sound pressure levels of the stimuli were approximately 60, 75, and 86 dB(A). The distances between the performer and the participant were 2, 8, and 32 m. In both conditions, participants were asked to produce the level of sound pressure matching the stimulus. Results show that when visual cues of musical performance are available, sound production had more robust loudness constancy than the sound level adjustment method.

The Effect of Frequency Acoustic Stimulation Sound on Intrauterine Weakening of Pregnant Sheep

Research to determine changes in intrauterine sound pressure in pregnant sheep after administration acoustic stimulation outside of the abdominal wall at some frequency sounds. The study was conducted at the Animal Hospital of Veterinary Faculty of Airlangga University. Pre test experimental design with pre- and post-test one group to assess intra-uterine sound pressure changes. The study was conducted at two lambs pregnant aterm after acoustic stimulation at a distance of 10 cm from the surface of the abdominal wall to the sound pressure 80,85,90,95 and 100 decibels and sound frequency of 31.5, 63, 125, 250, 500, 1000, 2000, 4000, 6000 and 8000 hertz. The results showed that the difference between the sound pressure outside of the abdominal wall with intrauterine sound pressure on both the pregnant sheep by an average of 16.7570 ± 8.0797 decibels. This shows their weakening sound after passing through the abdominal wall and the uterine wall. By using a paired t-test, this weakening statistically significant. At frequencies from 31.5 to 1000 hertz weakening values from 5.2 to 17.1 decibels while in 2000-8000 hertz frequency weakening value of 20.2 to 30.8 decibels. The conclusion that the stimulation of noise from outside the walls of the abdomen weakening sound after penetrating the abdominal wall and the uterine wall. Weakening occur at every level of sound pressure and at every level of a given frequency. Weakening value becomes greater at frequencies above 1000 hertz. Keywords: weakening, sound pressure, sound frequency, pregnant sheep.