Low‐frequency sound source for various acoustical oceanography and seafloor exploration applications

1993 ◽  
Vol 93 (4) ◽  
pp. 2380-2380
Author(s):  
Dimitri M. Donskoy
Keyword(s):  
Sound Source ◽  
Low Frequency ◽  
Frequency Sound

Low-Frequency Sound Source with Dual Bending Radiation Surfaces

1998 ◽  
Vol 37 (Part 1, No. 5B) ◽  
pp. 3161-3165 ◽  
Author(s):  
Mitsuru Yamamoto ◽  
Hiroshi Ishimura ◽  
Yoshinori Hama ◽  
Takeshi Inoue
Keyword(s):  
Sound Source ◽  
Low Frequency ◽  
Frequency Sound

Subjective evaluation of the combining effect between the virtual bass and head related transfer functions

2021 ◽  
Vol 263 (5) ◽  
pp. 1488-1496
Author(s):  
Yunqi Chen ◽  
Chuang Shi ◽  
Hao Mu
Keyword(s):  
Fundamental Frequency ◽  
Sound Source ◽  
Transfer Functions ◽  
Subjective Evaluation ◽  
Low Frequency ◽  
Localization Accuracy ◽  
Frequency Sound ◽  
Listening Tests ◽  
Listening Experience ◽  
Missing Fundamental

Earphones are commonly equipped with miniature loudspeaker units, which cannot transmit enough power of low-frequency sound. Meanwhile, there is often only one loudspeaker unit employed on each side of the earphone, whereby the multi-channel spatial audio processing cannot be applied. Therefore, the combined usage of the virtual bass (VB) and head-related transfer functions (HRTFs) is necessary for an immersive listening experience with earphones. However, the combining effect of the VB and HRTFs has not been comprehensively reported. The VB is developed based on the missing fundamental effect, providing that the presence of harmonics can be perceived as their fundamental frequency, even if the fundamental frequency is not presented. HRTFs describe the transmission process of a sound propagating from the sound source to human ears. Monaural audio processed by a pair of HRTFs can be perceived by the listener as a sound source located in the direction associated with the HRTFs. This paper carries out subjective listening tests and their results reveal that the harmonics required by the VB should be generated in the same direction as the high-frequency sound. The bass quality is rarely distorted by the presence of HRTFs, but the localization accuracy is occasionally degraded by the VB.

SOFTWARE DEVELOPMENT FOR ESTIMATION OF LOW FREQUENCY SOUND PROPAGATION IN GAS GUIDES OF POWER PLANTS TAKING TO ACCOUNT ACTIVE SOUND SOURCES

2020 ◽  
Vol 5 (4) ◽  
pp. 36-44
Author(s):  
A V Vasilyev
Keyword(s):  
Sound Source ◽  
Power Plants ◽  
Sound Propagation ◽  
Combustion Engine ◽  
Source Parameters ◽  
Low Frequency ◽  
Sound Sources ◽  
Software Application ◽  
Frequency Sound ◽  
Exhaust Noise

This paper is devoted to the problems of modelling and calculation of propagation of low frequency sound in gas guides of power plants taking to account active sound sources. The structure of software for prediction and calculation of low-frequency sound propagation in gas guides have described. Software uses four-pole method and takes to account radiation from additional (active) sound course. By using software it is possible to estimate sound source parameters to provide efficient sound attenuation. Examples of software application to calculation of intake and exhaust noise of internal combustion engine are described. The results of calculations show the possibilities of four-pole method software using to design acoustically the parameters of gas guides and mufflers for the different fields of applications.

Maximum output of a low frequency sound source using giant magnetostrictive material

1997 ◽  
Vol 258 (1-2) ◽  
pp. 87-92 ◽  
Author(s):  
H. Wakiwaka ◽  
K. Aoki ◽  
T. Yoshikawa ◽  
H. Kamata ◽  
M. Igarashi ◽  
...  
Keyword(s):  
Sound Source ◽  
Low Frequency ◽  
Maximum Output ◽  
Magnetostrictive Material ◽  
Frequency Sound ◽  
Giant Magnetostrictive Material

A modified electro-acoustical reciprocity method for measuring low-frequency sound source in arbitrary surroundings

2017 ◽  
Vol 116 ◽  
pp. 1-8 ◽  
Author(s):  
Ling Lu ◽  
Hongling Sun ◽  
Ming Wu ◽  
Qiaoxi Zhu ◽  
Jun Yang
Keyword(s):  
Sound Source ◽  
Low Frequency ◽  
Frequency Sound ◽  
Reciprocity Method

Tow‐powered low‐frequency sound source

1983 ◽  
Vol 74 (S1) ◽  
pp. S83-S83
Author(s):  
H. C. Schau ◽  
A. L. Van Buren ◽  
F. J. Radosta
Keyword(s):  
Sound Source ◽  
Low Frequency ◽  
Frequency Sound

Low Frequency Measurement by Synchronized Integrating Method and Influence of Reflecting Object

1983 ◽  
Vol 2 (2) ◽  
pp. 85-95 ◽  
Author(s):  
H. Fukuhara ◽  
T. Ohkuma
Keyword(s):  
Sound Source ◽  
Integral Method ◽  
Sound Propagation ◽  
Low Frequency ◽  
Noise Pollution ◽  
Frequency Measurement ◽  
Quantitative Investigation ◽  
Frequency Sound ◽  
Measurement And Analysis ◽  
Reflecting Surfaces

Concern over noise pollution led to the development of methods for making environmental assessments. At the same time, the need arose for methods to measure low frequency sound and clarify propagation conditions. The main objective of this research was to investigate low frequency sound propagation conditions and the problems associated with measurement and analysis. We also studied the characteristics of low frequency sound (below 100 Hz) near reflecting surfaces and developed a technique for positioning the measurement microphones. Additionally we found it necessary to develop a new measurement method we call “the synchronized integral” method. A theoretically perfect point sound source was needed for the measurements. To satisfy this need, we constructed a source for quantitative investigation and measurements were made at distances up to 100 m from the sound source. Analysis of the data we collected clarified the following phenomena: −6 dB/-doubling distance (d.d) attenuation is not reached; frequency and microphone height influence attenuation; measurements taken near the ground are most stable; superposition influence occurs at frequencies above 125 Hz.

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