Monitoring Air-sea Exchange Processes Using the Ambient Sound Field

1997 ◽  
Author(s):  
Jeffrey A. Nystuen
Keyword(s):  
Sound Field ◽  
Ambient Sound ◽  
Exchange Processes

scholarly journals Measuring the Marine Soundscape of the Indian Ocean with Southern Elephant Seals Used as Acoustic Gliders of Opportunity

2017 ◽  
Vol 34 (1) ◽  
pp. 207-223 ◽  
Author(s):  
Dorian Cazau ◽  
Julien Bonnel ◽  
Joffrey Jouma’a ◽  
Yves le Bras ◽  
Christophe Guinet
Keyword(s):  
Indian Ocean ◽  
Low Frequency ◽  
Sound Field ◽  
Elephant Seals ◽  
Ambient Sound ◽  
Southern Elephant Seals ◽  
Operational Systems ◽  
The Indian Ocean ◽  
Passive Acoustic ◽  
Free Ranging

AbstractThe underwater ambient sound field contains quantifiable information about the physical and biological marine environment. The development of operational systems for monitoring in an autonomous way the underwater acoustic signal is necessary for many applications, such as meteorology and biodiversity protection. This paper develops a proof-of-concept study on performing marine soundscape analysis from acoustic passive recordings of free-ranging biologged southern elephant seals (SES). A multivariate multiple linear regression (MMLR) framework is used to predict the measured ambient noise, modeled as a multivariate acoustic response, from SES (depth, speed, and acceleration) and environmental (wind) variables. Results show that the acoustic contributions of SES variables affect mainly low-frequency sound pressure levels (SPLs), while frequency bands above 3 kHz are less corrupted by SES displacement and allow a good measure of the Indian Ocean soundscape. Also, preliminary results toward the development of a mobile embedded weather sensor are presented. In particular, wind speed estimation can be performed from the passive acoustic recordings with an accuracy of 2 m s−1, using a rather simple multiple linear model.

Echolocation Reconsidered: Using Spatial Variations in the Ambient Sound Field to Guide Locomotion

1998 ◽  
Vol 92 (9) ◽  
pp. 615-632 ◽  
Author(s):  
Daniel H. Ashmead ◽  
Robert S. Wall ◽  
Susan B. Eaton ◽  
Kiara A. Ebinger ◽  
Mary-Maureen Snook-Hill ◽  
...  
Keyword(s):  
High Frequency ◽  
Visual Impairments ◽  
Low Frequency ◽  
Sound Field ◽  
Spatial Variations ◽  
Frequency Sound ◽  
Ambient Sound ◽  
Children With Visual Impairments

This article presents an acoustical model and evidence from four experiments that children with visual impairments use the buildup of low-frequency sound along walls to guide locomotion. The model differs from the concept of echolocation by emphasizing sound that is ambient, rather than self-produced, and of low, rather than high, frequency.

Spatial uniformity tolerances for sound masking systems in open-plan offices

2021 ◽  
Vol 263 (1) ◽  
pp. 5643-5649
Author(s):  
Roderick Mackenzie ◽  
Farideh Zarei ◽  
Vincent Le Men
Keyword(s):  
Sound Field ◽  
Sound Level ◽  
Fine Grid ◽  
Office Space ◽  
Ambient Sound ◽  
Spatial Uniformity ◽  
Field Uniformity ◽  
Open Plan ◽  
Discrete Measurement ◽  
Sound Masking

Electronic sound masking systems raise the ambient sound level in offices to a controlled minimum sound level in order to increase speech privacy and reduce distractions. Sound masking systems are calibrated to provide the most uniform sound field achievable, as a spatially non-uniform masking sound field could result in occupant perception and uneven speech privacy conditions. Tolerances for acceptable spatial uniformity vary between specifiers, and may be based on different evaluation methods using only a few discrete measurement points to represent an entire office space. However, the actual uniformity of a masking sound field across an office, and the parameters influencing it, has not been widely investigated. Thus, this study aims to investigate the masking sound uniformity in a typical open-plan office space using fine-grid measurements conforming to measurement method of ASTM E1573-18. Percentages of measured locations where the sound pressure levels were within specified tolerances (with increments of 0.5 dB) were calculated using the measured 1/3 octave band levels. The research also utilized geometric acoustical simulations to investigate how physical office parameters (number of loudspeakers, partition heights, ceiling absorption, and diffusion characteristics) affect the sound field uniformity of the sound masking system.

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