Regulatory Mechanism of Voice Intensity Variation

1964 ◽  
Vol 7 (1) ◽  
pp. 17-29 ◽  
Author(s):  
Nobuhiko Isshiki
Keyword(s):  
Flow Rate ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Low Frequency ◽  
Intensity Variation ◽  
Pressure Level ◽  
Expiratory Muscle ◽  
Laryngeal Control ◽  
The Relationship ◽  
The Voice

The relationship between the voice intensity (sound pressure level), the subglottic pressure, the air flow rate, and the glottal resistance was investigated. Simultaneous recordings were made of the sound pressure level of voice, the subglottic pressure, the flow rate, and the volume of air utilized during phonation. The glottal resistance, the subglottic power, and the efficiency of voice were calculated from the data. It was found that on very low frequency phonation the flow rate remained almost unchanged or even slightly decreased with the increase in voice intensity while the glottal resistance showed a tendency to augment with increased voice intensity. In contrast to this, the flow rate on high frequency phonation was found to increase greatly, while the glottal resistance remained almost unchanged as the voice intensity increased. On the basis of the data it was concluded that at very low pitches, the glottal resistance is dominant in controlling intensity (laryngeal control), becoming less so as the pitch is raised, until at extremely high pitch the intensity is controlled almost entirely by the flow rate (expiratory muscle control).

Gyro Rock Crusher and Asphalt Plant Sound Power Levels

2012 ◽  
Author(s):  
Henry A. Scarton ◽  
Kyle R. Wilt
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Low Frequency ◽  
Pressure Level ◽  
Sound Power ◽  
Far Field ◽  
Atmospheric Attenuation ◽  
Frequency Sound ◽  
Sound Pressure Levels ◽  
Rock Crusher

Sound power levels including the distribution into octaves from a large 149 kW (200 horsepower) gyro rock crusher and separate asphalt plant are presented. These NIST-traceable data are needed for estimating sound pressure levels at large distances (such as occurs on adjoining property to a quarry) where atmospheric attenuation may be significant for the higher frequencies. Included are examples of the computed A-weighted sound pressure levels at a distance from the source, including atmospheric attenuation. Substantial low-frequency sound power levels are noted which are greatly reduced in the far-field A-weighted sound pressure level calculations.

scholarly journals Noise-silencing technology for upright venting pipe jet noise

2018 ◽  
Vol 10 (8) ◽  
pp. 168781401879481 ◽  
Author(s):  
Enbin Liu ◽  
Shanbi Peng ◽  
Tiaowei Yang
Keyword(s):  
Natural Gas ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Low Frequency ◽  
Jet Noise ◽  
Pressure Level ◽  
Living Environment ◽  
Frequency Noise ◽  
Frequency Range ◽  
Expansion Chamber

When a natural gas transmission and distribution station performs a planned or emergency venting operation, the jet noise produced by the natural gas venting pipe can have an intensity as high as 110 dB, thereby severely affecting the production and living environment. Jet noise produced by venting pipes is a type of aerodynamic noise. This study investigates the mechanism that produces the jet noise and the radiative characteristics of jet noise using a computational fluid dynamics method that combines large eddy simulation with the Ffowcs Williams–Hawkings acoustic analogy theory. The analysis results show that the sound pressure level of jet noise is relatively high, with a maximum level of 115 dB in the low-frequency range (0–1000 Hz), and the sound pressure level is approximately the average level in the frequency range of 1000–4000 Hz. In addition, the maximum and average sound pressure levels of the noise at the same monitoring point both slightly decrease, and the frequency of the occurrence of a maximum sound pressure level decreases as the Mach number at the outlet of the venting pipe increases. An increase in the flow rate can result in a shift from low-frequency to high-frequency noise. Subsequently, this study includes a design of an expansion-chamber muffler that reduces the jet noise produced by venting pipes and an analysis of its effectiveness in reducing noise. The results show that the expansion-chamber muffler designed in this study can effectively reduce jet noise by 10–40 dB and, thus, achieve effective noise prevention and control.

Loudness of Structure-Borne Sound Heard Directly by Ear Put on Vibrating Structure

2003 ◽  
Vol 22 (1) ◽  
pp. 27-32
Author(s):  
Takuya Fujimoto
Keyword(s):  
Sound Pressure Level ◽  
Contact Surface ◽  
Vibration Amplitude ◽  
Sound Pressure ◽  
Pressure Level ◽  
Vibration Velocity ◽  
The Relationship ◽  
Velocity Level

Putting an ear close to a vibrating structure like a wall or a floor, we are able to hear structure-borne sounds clearly, but the loudness of such sounds has never been studied quantitatively. In this study, subjective experiments were carried out in order to obtain the relationship between loudness and the vibration amplitude of the ear's contact surface at low audible frequencies. The main result of this study is that the loudness of a structure-borne sound is almost equal to that of an air-borne sound with a sound pressure level 20 dB higher than the vibration velocity level (ref=5×10−8 m/s) of the surface. According to this result, the loudness of the structure-borne sound heard directly can be evaluated as a sound pressure level derived from the measured vibration amplitude of the structure.

scholarly journals Development of an on-site system for measuring the low-frequency noise and complainant’s responses

2018 ◽  
Vol 37 (2) ◽  
pp. 373-384
Author(s):  
Hiroshi Sato ◽  
Jongkwan Ryu ◽  
Kenji Kurakata
Keyword(s):  
Time Trends ◽  
Sound Pressure ◽  
Low Frequency ◽  
Dominant Frequency ◽  
Pressure Level ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Measurement Results ◽  
Frequency Components ◽  
The Relationship

An on-site system for measuring low-frequency noise and complainant's responses to the low-frequency noise was developed to confirm whether the complainant suffer from the environmental noise with low-frequency components. The system suggests several methods to find the dominant frequency and major sound pressure level spectrum of the noise causing annoyance. This method can also yield a quantified relationship (correlation coefficient and percentage of response to the noise) between physical noise properties and the complainant’s responses. The advantage of this system is that it can easily find the relationship between the complainant’s response to the acoustic event of the houses and the physical characteristics of the low-frequency noise, such as the time trends and frequency characteristics. This paper describes the developed system and provides an example of the measurement results.

The Relationship Between Nasal Sound Pressure Level and Palatopharyngeal Closure

1969 ◽  
Vol 12 (1) ◽  
pp. 193-198 ◽  
Author(s):  
Ralph L. Shelton ◽  
William B. Arndt ◽  
Albert W. Knox ◽  
Mary Elbert ◽  
Linda Chisum ◽  
...  
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Correlation Coefficients ◽  
Pressure Level ◽  
The Difference ◽  
The Relationship

A group of 21 subjects with well-fitted speech bulbs was compared for nasal sound pressure level (SPL) with a group of 13 subjects having moderate deficiency of palatopharyngeal closure. The difference in mean measures for the two groups was statistically significant. Correlation coefficients are reported for the relationships between nasal SPL and both a cinefluorographic measure of palatopharyngeal closure and several articulation measures.

Study on acoustic environment of canteens in South China University of Technology

2021 ◽  
Vol 263 (5) ◽  
pp. 1695-1702
Author(s):  
Ziyu Zhou ◽  
Hongwei Wang
Keyword(s):  
South China ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Noise Sources ◽  
Acoustic Environment ◽  
University Of Technology ◽  
Different Types ◽  
Satisfaction Evaluation ◽  
The Voice

In order to understand the characteristics of the acoustic environment of University canteens, the canteens of South China University of Technology were selected as the research objects, and the acoustic parameters were measured on the spot and the questionnaire survey was conducted. The results show that the average sound pressure level of restaurants with smaller area is lower than that of restaurants with larger area, and the sound pressure level of dining space first increases rapidly, then increases slowly, and finally remains unchanged with the increase of the number of diners. In the aspect of restaurant acoustic environment satisfaction evaluation, the space with the smallest dining area has the highest acoustic environment satisfaction evaluation level, and the collision sound of tableware collection and table and chair moving has the highest correlation with the acoustic environment satisfaction evaluation. In terms of different types of noise sources, diners think that the most disturbing noise for conversation is the voice of the surrounding people, followed by the collision of tables and chairs and the collection of tableware, and the least disturbing noise is the noise of air conditioning and kitchen equipment.

scholarly journals Changes to respiratory mechanisms during speech as a result of different cues to increase loudness

2005 ◽  
Vol 98 (6) ◽  
pp. 2177-2184 ◽  
Author(s):  
Jessica E. Huber ◽  
Bharath Chandrasekaran ◽  
John J. Wolstencroft
Keyword(s):  
Young Adults ◽  
Respiratory System ◽  
Sound Pressure Level ◽  
Lung Volume ◽  
Neural Control ◽  
Sound Pressure ◽  
Speech Rate ◽  
Muscle Tension ◽  
Pressure Level ◽  
Expiratory Muscle

The purpose of the present study was to determine whether different cues to increase loudness in speech result in different internal targets (or goals) for respiratory movement and whether the neural control of the respiratory system is sensitive to changes in the speaker's internal loudness target. This study examined respiratory mechanisms during speech in 30 young adults at comfortable level and increased loudness levels. Increased loudness was elicited using three methods: asking subjects to target a specific sound pressure level, asking subjects to speak twice as loud as comfortable, and asking subjects to speak in noise. All three loud conditions resulted in similar increases in sound pressure level . However, the respiratory mechanisms used to support the increase in loudness differed significantly depending on how the louder speech was elicited. When asked to target at a particular sound pressure level, subjects used a mechanism of increasing the lung volume at which speech was initiated to take advantage of higher recoil pressures. When asked to speak twice as loud as comfortable, subjects increased expiratory muscle tension, for the most part, to increase the pressure for speech. However, in the most natural of the elicitation methods, speaking in noise, the subjects used a combined respiratory approach, using both increased recoil pressures and increased expiratory muscle tension. In noise, an additional target, possibly improving intelligibility of speech, was reflected in the slowing of speech rate and in larger volume excursions even though the speakers were producing the same number of syllables.

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