scholarly journals Detection of infrasound by the Atlantic cod

1986 ◽  
Vol 125 (1) ◽  
pp. 197-204 ◽  
Author(s):  
O. Sand ◽  
H. E. Karlsen
Keyword(s):  
Ambient Noise ◽  
Atlantic Cod ◽  
Low Frequency ◽  
Directional Pattern ◽  
Frequency Noise ◽  
Threshold Values ◽  
Sensory Inputs ◽  
A Value ◽  
Cardiac Conditioning ◽  
Lower Frequencies

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.

Effects of Noise Frequency on Performance and Annoyance for Women and Men

1981 ◽  
Vol 52 (2) ◽  
pp. 435-441 ◽  
Author(s):  
Kelli F. Key ◽  
M. Carr Payne
Keyword(s):  
Sex Differences ◽  
Magnitude Estimation ◽  
High Frequency ◽  
Ambient Noise ◽  
Direct Relationship ◽  
Low Frequency ◽  
Frequency Noise ◽  
Complex Task ◽  
High Frequency Noise ◽  
Noise Frequency

Effects of noise frequencies on both performance on a complex psychomotor task and annoyance were investigated for men ( n = 30) and women ( n = 30). Each subject performed a complex psychomotor task for 50 min. in the presence of low frequency noise, high frequency noise, or ambient noise. Women and men learned the task at different rates. Little effect of noise was shown. Annoyance ratings were subsequently obtained from each subject for noises of various frequencies by the method of magnitude estimation. High frequency noises were more annoying than low frequency noises regardless of sex and immediate prior exposure to noise. Sex differences in annoyance did not occur. No direct relationship between learning to perform a complex task while exposed to noise and annoyance by that noise was demonstrated.

scholarly journals The Inner Ear is Responsible for Detection of Infrasound in the Perch (Perca Fluviatilis)

1992 ◽  
Vol 171 (1) ◽  
pp. 163-172 ◽  
Author(s):  
HANSERIK KARLSEN
Keyword(s):  
Inner Ear ◽  
Lateral Line ◽  
Low Frequency ◽  
Perca Fluviatilis ◽  
Lateral Line System ◽  
Threshold Values ◽  
Line System ◽  
Frequency Detection ◽  
Perch Perca Fluviatilis ◽  
Cardiac Conditioning

In a previous study of infrasound detection in the cod, the inner ear was suggested to be the sensory organ responsible for the responses. However, a possible involvement of the lateral-line system in the observed low-frequency detection could not be ruled out. The infrasound sensitivity was therefore studied in perch (Perca fluviatilis) with normal and blocked lateral-line organs. The experiments were performed using a standing wave acoustic tube and the cardiac conditioning technique. All perch readily responded to infrasound frequencies down to 0.3 Hz with threshold values of approximately 2×10−4 ms−2. These thresholds were not affected by complete blocking of the lateral-line system with Co2+, which suggests that the inner ear is responsible for the observed infrasound detection by the perch.

scholarly journals Влияние протонного облучения (15 МэВ) на низкочастотный шум мощных SiC MOSFETs

2019 ◽  
Vol 53 (12) ◽  
pp. 1604
Author(s):  
А.А. Лебедев ◽  
М.Е. Левинштейн ◽  
П.А. Иванов ◽  
В.В. Козловский ◽  
А.М. Стрельчук ◽  
...  
Keyword(s):  
Good Accuracy ◽  
Dose Range ◽  
Low Frequency ◽  
Frequency Noise ◽  
Saturation Current ◽  
Low Frequency Noise ◽  
A Value ◽  
Noise Spectroscopy ◽  
Noise Density ◽  
Output Characteristics

Low frequency noise has been studied in power4H-SiC MOSFETs after proton(15 MeV) irradiation. The noise was studied at room temperature in the frequency range 1 Hz−50 kHz after irradiation with doses of 1012 ≤Ф≤ 6•1013 cm−2. Frequency dependence of the spectral noise density SI follows with good accuracy to the law SI∝1/f. The correlation between the saturation current of the output characteristics of Id(Vd) and the level of low-frequency noise is established. In the dose range Ф studied the value of the saturation current varies within about 20%, while the noise level changes by 2orders of magnitude. From the data of noise spectroscopy, the density of traps in the gate oxide, Ntv was estimated. In non-irradiated structures Ntv ≈5.4•1018cm−3•eV−1, at  = 6•1013 cm−2, Ntv increases to a value of Ntv ≈7.2•1019cm−3•eV−1.

scholarly journals Ambient noise from ocean surf drives frequency shifts in non-passerine bird song

2020 ◽  
Author(s):  
Matteo Sebastianelli ◽  
Daniel T. Blumstein ◽  
Alexander N. G. Kirschel
Keyword(s):  
Background Noise ◽  
Ambient Noise ◽  
Selective Pressure ◽  
Low Frequency ◽  
Vocal Learning ◽  
Passerine Bird ◽  
Anthropogenic Noise ◽  
Masking Effect ◽  
Frequency Noise ◽  
Natural Noise

AbstractEffective communication in birds is often hampered by background noise, with many recent studies focusing on the effect of anthropogenic noise on passerine bird song. Continuous low-frequency natural noise is predicted to drive changes in both frequency and temporal patterning of bird vocalizations, but the extent to which these effects may also affect birds that lack vocal learning is not yet fully understood. Here we use a gradient of exposure to natural low-frequency noise to assess whether it exerts selective pressure on vocalizations in a species whose songs are innate. We tested whether three species of Pogoniulus tinkerbirds adapt their song when exposed to a source of continuous low-frequency noise from ocean surf. We show that dominant frequency increases the closer birds are to the coast in all the three species, and in line with higher noise levels, indicating that ocean surf sound may apply a selective pressure on tinkerbird songs. As a consequence, tinkerbirds adapt their songs with an increase in frequency to avoid the masking effect due to overlapping frequencies with ambient noise, therefore improving long-range communication with intended receivers. Our study provides for the first time, compelling evidence that natural ambient noise affects vocalizations in birds whose songs are developed innately. We believe that our results can also be extrapolated in the context of anthropogenic noise pollution, hence providing a baseline for the study of the effects of low-frequency ambient noise on birds that lack vocal learning.Significance StatementBirdsong is constantly under selection as it mediates key interactions such as mate attraction, competition with same-sex individuals for reproduction and competition with heterospecifics for space-related resources. Any phenomenon that interferes with communication can therefore have a profound impact on individual fitness. Passerines are more likely to avoid the masking effect of background noise because of their higher vocal flexibility. Many non-passerine species lacking such flexibility might therefore be more vulnerable to the negative effects on their fitness of exposure to low-frequency background noise. Species incapable of adapting their signals to background noise are predicted to disappear from noisy areas. Despite this, we show that species that lack song learning may show an adaptive response to natural noise which may develop over evolutionary timescales.

Infrasound Sensitivity in the Plaice (Pleuronectes Platessa)

1992 ◽  
Vol 171 (1) ◽  
pp. 173-187 ◽  
Author(s):  
HANS ERIK KARLSEN
Keyword(s):  
Resonant Frequency ◽  
Test Chamber ◽  
Low Frequency ◽  
Harmonic Oscillators ◽  
Otolith Organs ◽  
Threshold Values ◽  
Frequency Range ◽  
Pleuronectes Platessa ◽  
Steel Wires ◽  
Cardiac Conditioning

The sensitivity of plaice (Pleuronectes platessa) to infrasound has been examined using a seawater-filled test chamber suspended by steel wires like a swing and driven by a vibrator. The sensitivity to low-frequency vibrations was determined using the cardiac conditioning technique. All plaice readily responded to infrasound down to 0.1 Hz, which was the lowest frequency tested, with threshold values of approximately 4×10−5 ms−2 rms. This sensitivity is comparable to infrasound thresholds found in other fish species and it agrees with the acceleration thresholds for plaice in the frequency range 30–100 Hz. The water movements relative to the fish surface produced during stimulation were below lateral-line thresholds. The inner ear otolith organs are thus probably responsible for the observed responses to infrasound. The hearing capabilities of plaice may be explained by these organs functioning as slightly underdamped harmonic oscillators with a resonant frequency close to 100Hz.

Study of Sound Insulation of Control Cabins in Industry in the Low Frequency Range

1992 ◽  
Vol 11 (2) ◽  
pp. 42-46
Author(s):  
Anna Kaczmarska ◽  
Danuta Augustyriska
Keyword(s):  
Noise Reduction ◽  
Sound Pressure ◽  
Low Frequency ◽  
Machine Building ◽  
Sound Insulation ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Frequency Range ◽  
Sound Pressure Levels ◽  
Lower Frequencies

The number of control cabins installed in industry has increased considerably during the last few years. Most cabins installed nowadays show a satisfactory noise reduction in the frequency range above 500 Hz. The effect of noise damping however shows a gradual decrease for lower frequencies. The present paper is a description of the distribution of low frequency noise in different types of control cabins installed in typical low frequency noise environments in steel plants and the machine building industry. Measurements were made in 20 control cabins, constructed of metal and stone Measurements of sound pressure levels in octave bands were made inside and outside the cabins. The sound pressure level in octave bands in the low frequency range (4–31.5 Hz) inside the cabins was high and varied between 60–108 dB. This is probably due to the insufficient noise reduction for lower frequencies. In some control cabins there was an increased level of low frequency noise inside the cabin compared to the outside. In these control cabins sound pressure levels exceed the admissible values according to Polish standards. The increase of noise level within the low frequency range is considered to be based on resonances.

scholarly journals Acoustic Properties of Two Urban Song Dialects in the Orange-Tufted Sunbird (Nectarinia Osea)

The Auk ◽  
2005 ◽  
Vol 122 (1) ◽  
pp. 231-245 ◽  
Author(s):  
Noam Leader ◽  
Jonathan Wright ◽  
Yoram Yom-Yov
Keyword(s):  
Ambient Noise ◽  
Low Frequency ◽  
Acoustic Properties ◽  
Habitat Modification ◽  
Frequency Noise ◽  
Maximum Frequency ◽  
Atmospheric Conditions ◽  
Anthropogenic Habitat ◽  
Song Dialects ◽  
Song Types

AbstractBiologically important acoustic signals must be transmitted from a signaler to a receiver. Over distance, however, sounds may undergo modification through attenuation, degradation, and masking. Recent anthropogenic habitat modification occurring in many places—in urban habitats, in particular—has rapidly changed local topography and atmospheric conditions and generated new patterns of noise that are likely to interfere with communicative signals. As part of a study of microgeographic song dialects in an urban population of Orange-tufted Sunbirds (Nectarinia osea) in Israel, we examined the environmental influences on song transmission and reception in a rapidly developing human-altered environment. We examined the physical properties of the two dialect song types, which exhibit a large difference of 2–3 kHz in the maximum frequency of the trill, using sound transmission measurements to test how both song types propagate through a highly obstructed habitat of buildings and vegetation. Additionally, we examined how ambient noise—in particular, low-frequency noise arising mainly from automobile traffic—affects the transmission of both dialect songs. Finally, using song playback, we investigated the consequences of sound degradation on dialect recognition and discrimination by sunbirds. The dialect containing higher frequencies in the trill was found to undergo severe frequency-dependent attenuation, in which the maximum frequency of the trill notes drops by >2 kHz over a distance of 70–100 m (less than two territories away). Also, the possibility that the use of higher frequencies in that dialect group's song is intended to overcome masking by urban ambient noise, which is concentrated mainly in lower frequencies, was not supported by our findings. Males singing the high dialect responded differently to playbacks of an intact and an attenuated form of their dialect song. Taken together, our results suggest that the dialect containing higher frequencies in the trill may be unsuitable for effective long-range transmission through this particular sunbird habitat.Propiedades Acústicas de Dos Dialectos del Canto Urbano de Nectarinia osea

Estimating the Quality of Thermionic Cathodes for Microwave Vacuum Tubes Using the Low-Frequency Noise Parameters

Vestnik MEI ◽  
2018 ◽  
Vol 5 (5) ◽  
pp. 120-127
Author(s):  
Mikhail D. Vorobyev ◽  
◽  
Dmitriy N. Yudaev ◽  
Andrey Yu. Zorin ◽  
◽  
...  
Keyword(s):  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Noise Parameters ◽  
Thermionic Cathodes ◽  
Vacuum Tubes
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