Trends in low frequency ambient noise for a site 80 km off the Oregon coast over approximately four years ending August 2020

2021 ◽  
Vol 149 (4) ◽  
pp. A87-A87
Author(s):  
Peter H. Dahl ◽  
Michael Harrington ◽  
David R. Dall'Osto
2015 ◽  
Author(s):  
Rabah Bensalem* ◽  
Djamal Machane ◽  
Jean-Luc Chatelain ◽  
Mohamed Djeddi ◽  
Hakim Moulouel ◽  
...  

2009 ◽  
Vol 36 (2-3) ◽  
pp. 259-279 ◽  
Author(s):  
Rosa María Rojas Torres

This article offers a treatment of the linguistic category ‘adjective’ that appears in two colonial sources, both written by Fray Juan de Córdova, O.P. in 1578: theArte del idioma zapotecoand theVocabulario en lengua çapoteca. Juan de Córdova was a Dominican friar, born in Córdoba, Spain in probably 1501. In 1543, Juan de Córdova was ordained at the Convento Imperial de México and later was sent to the Dominican Monastery of Oaxaca. He served as Province Minister for two years — from 1568 to 1570 — and later he continued to be a missionary among the Zapotec, when he wrote his great work on their language. Toward the end of his life, Juan de Córdova returned to Oaxaca and died in the Dominican Monastery of Old Antequera in 1595.
Based on the description of the category of the adjective, as proposed by Córdova and the analysis of the language as is currently spoken, particularly in the area of Santa Ana del Valle, Oaxaca, the author will show that the grammatical class proposed by Córdova was not actually formed as such during the period he describes. It will be shown, based on the analysis of two colonial texts — thetestamentosby Gabriel Luis (1610) and Juan López (1618) — that the words that Cordova calls adjectives not only occur with very low-frequency but, more crucially, their categorization as adjectives has been due to their role in the Spanish translations more than to their grammatical characteristics. These two testaments had been compiled, with other testaments and documents of several kinds, namely as documents in a legal suit concerning a site named Gueguecahui. It is relevant to mention that testaments are not very reliable kind of document for a syntactic analysis of the language, since they have a very rigid structure that apparently mimics the schema used in testaments written in Spanish. Nevertheless, they can show that the attributive modification function is seldom used, and the cases found do not support that these expressions really pertain to the syntactic category of adjectives.
Furthermore, the analysis of adjectives as currently used in the Zapotec of Santa Ana del Valle shows that, more often than not, they do not correspond to adjectives but indeed verbs in Cordova’sVocabulario. This affirmation is based on a comparative analysis of some adjectives in modern Zapotec of Santa Ana del Valle with related words given adjectival meanings in Cordova´sVocabulario. In conclusion there is not enough evidence of the existence of adjective category in 16th-century Zapotec.


1986 ◽  
Vol 125 (1) ◽  
pp. 197-204 ◽  
Author(s):  
O. Sand ◽  
H. E. Karlsen

Below about 50 kHz the level of ambient noise in the sea increases continuously towards lower frequencies. In the infrasound range the spectral slope is particularly steep. This low-frequency noise may propagate long distances with little attenuation, causing a directional pattern of infrasound in the sea. Using a standing-wave acoustic tube, we have studied the sensitivity of cod to infrasound down to 0.1 Hz by means of the cardiac conditioning technique. The threshold values, measured as particle acceleration, showed a steady decline towards lower frequencies below 10 Hz, reaching a value close to 10(−5)ms-2 at 0.1 Hz. The spectrum level at 0.1 Hz in the sea ranges between 120 and 180 dB (re 1 microPa), with corresponding particle accelerations from less than 10(−6) to more than 10(−4)ms-2. The sensitivity of cod is thus sufficient to detect the highest levels of ambient infrasound, and we put forward the hypothesis that fish may utilize information about the infrasound pattern in the sea for orientation during migration, probably in addition to an array of other sensory inputs.


1988 ◽  
pp. 273-280
Author(s):  
Henrik Schmidt ◽  
Tuncay Akal ◽  
W. A. Kuperman

2018 ◽  
Vol 89 (4) ◽  
pp. 1488-1496 ◽  
Author(s):  
M. Schimmel ◽  
E. Stutzmann ◽  
S. Ventosa

2019 ◽  
Vol 105 (5) ◽  
pp. 875-887
Author(s):  
Florian Pausch ◽  
Janina Fels

Virtual acoustic environments have demonstrated their versatility for conducting studies in various research areas as they allow easy manipulations of experimental test conditions or simulated acoustic scenes, while providing expansion possibilities to related interdisciplinary and multimodal fields. Although the evolution of auditory and cognitive models is consistently pursued, listening experiments are still considered the gold standard, usually necessitating a large amount of resources, including travel expenses of study participants. In order to facilitate practical and efficient study execution, we therefore implemented a mobile hearing laboratory by acoustically optimising the interior of a caravan. All necessary technical facilities were integrated to perform listening experiments in virtual acoustic environments under controlled conditions directly on site, for example, in front of schools or senior residential centers. The design and construction of this laboratory are presented and evaluated based on insulation properties, selected room acoustic parameters, and interior ambient noise levels that are to be expected during operation at representative test sites. Limitations, particularly in low-frequency insulation performance, should provide incentives for further optimisations in similar future projects.


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