Elephants may be listening with their feet as well as with their ears, say researchers who are studying how well super-low frequency elephant song moves through the ground.
大象在用耳的同時，還能用腳傾聽——研究大象超低頻鳴叫地面?zhèn)鞑サ难芯咳藛T如是說。
For about 20 years it's been known that African elephants sing out and respond to calls so low that they are beyond human hearing. Until now, however, no one was sure if the rumbling calls were also moving through the Earth as seismic waves, possibly helping elephants communicate when there is too much noise above ground.
二十多年前科學家們就曾研究發(fā)現，非洲象會使用各種低頻聲音進行交談，這些低頻聲音甚至連人的耳朵也無法捕捉到。然而，在此之前誰也不曾料到這種“交談”會像地震波一樣通過地表傳播。當地面噪音過大時，大象們很有可能就是用這種方式進行交流。
"They are trying to prove the concept is possible," said elephant researcher Katy Payne of the Cornell University Bioacoustics Research Program, referring to a team of Stanford University researchers who have published a paper on seismic elephant infrasound calls in the current issue of Geophysical Research Letters.
《地球物理研究通訊》最近期發(fā)表了斯坦福大學的一組研究人員關于大象的地震波次聲傳播的一篇論文?？的螤柎髮W生物聲學研究項目的大象研究人員Katy Payne正根據這篇論文進行實驗，她說：“我們在試圖證明這個設想是可行的”。
"We have several experiments going on right now to try to determine whether elephants perceive seismic cues via bone through their toenails and foot bones to their middle ear bones, or through vibration-detecting cells in the bottom of the foot," said Stanford's Caitlin O'Connell-Rodwell, now studying the matter in Namibia.
正在納米比亞進行研究工作的斯坦福大學研究人員Caitlin O'Connell-Rodwell說：“我們目前正在進行數個實驗，用以斷定大象是否能通過趾甲、腳骨、中耳骨或者腳底的震動探測細胞來察覺到地震信號?！?BR> What is clear from the Stanford team's earlier work with trained African elephants is that under ideal conditions, elephant infrasound calls can make seismic waves that can travel almost a mile and a half （two kilometers）.
在通過馴服的非洲象進行的較早的研究中，斯坦福大學研究小組已清楚：理想條件下，大象的次聲吼叫能使震波傳播兩公里左右。
The seismic signals are identical to the elephant calls in the air, says O'Connell-Rodwell.
地震信號和大象在空氣中的鳴叫是相同的，O'Connell-Rodwell說。
But are the elephants really picking up distant seismic calls through their feet?
但大象們真的通過腳接收了遠端的地震信號嗎？
"It seems evident from their behavior," said O'Connell-Rodwell.
“從它們的動作來看，這是很明顯的，”O(jiān)'Connell-Rodwell說。
Telltale behaviors that an elephant is listening to a call include standing very still and adjusting their ears, explained Payne.
Payne解釋泄密的動作是：大象在傾聽時，總是靜靜佇立，并且調整他們的耳朵。
But since infrasound in the air is known to travel much further then a mile and a half （two kilometers）, it's hard to be sure if elephants ever notice the seismic side of their calls or use them as a back up "line" on noisy days.
但因為次聲在空氣中傳播的距離要遠大于兩公里，所以很難斷定大象是否留意到了地震波的信息，還是只是在地表嘈雜的日子把它作為一條備份“專線”。
To sort that out, the Stanford team is now sending elephant calls through the ground only and watching the reactions of wild elephants to see if it catches their attention.
為了區(qū)分清楚，斯坦福的研究小組現在正通過只給大象發(fā)送地震波，然后通過觀察野生動物的反映來判斷他們是否留意到地震波傳遞的信息。
"We are now conducting seismic playback experiments in Etosha National Park, Namibia, that will tell us for sure if they detect the signals," said O'Connell-Rodwell.
O'Connell-Rodwell說：“我們目前在納米比亞的Etosha國家公園進行地震波回放實驗，很快就能確定它們是否察覺了信號。”
As for whether the ground can also get too noisy for seismic elephant songs, O'Connell-Rodwell says it's possible. Generators, vehicles and airplanes all can make a lot of seismic noise and can easily drown out elephant calls entirely.
談到地表是否會因為別的震波而影響了大象的聲音傳播，O'Connell-Rodwell說這是可能的。發(fā)電機、車輛、飛機都能制造大量的地震波，而且輕易就把大象的聲音完全蓋過。
大象在用耳的同時，還能用腳傾聽——研究大象超低頻鳴叫地面?zhèn)鞑サ难芯咳藛T如是說。
For about 20 years it's been known that African elephants sing out and respond to calls so low that they are beyond human hearing. Until now, however, no one was sure if the rumbling calls were also moving through the Earth as seismic waves, possibly helping elephants communicate when there is too much noise above ground.
二十多年前科學家們就曾研究發(fā)現，非洲象會使用各種低頻聲音進行交談，這些低頻聲音甚至連人的耳朵也無法捕捉到。然而，在此之前誰也不曾料到這種“交談”會像地震波一樣通過地表傳播。當地面噪音過大時，大象們很有可能就是用這種方式進行交流。
"They are trying to prove the concept is possible," said elephant researcher Katy Payne of the Cornell University Bioacoustics Research Program, referring to a team of Stanford University researchers who have published a paper on seismic elephant infrasound calls in the current issue of Geophysical Research Letters.
《地球物理研究通訊》最近期發(fā)表了斯坦福大學的一組研究人員關于大象的地震波次聲傳播的一篇論文?？的螤柎髮W生物聲學研究項目的大象研究人員Katy Payne正根據這篇論文進行實驗，她說：“我們在試圖證明這個設想是可行的”。
"We have several experiments going on right now to try to determine whether elephants perceive seismic cues via bone through their toenails and foot bones to their middle ear bones, or through vibration-detecting cells in the bottom of the foot," said Stanford's Caitlin O'Connell-Rodwell, now studying the matter in Namibia.
正在納米比亞進行研究工作的斯坦福大學研究人員Caitlin O'Connell-Rodwell說：“我們目前正在進行數個實驗，用以斷定大象是否能通過趾甲、腳骨、中耳骨或者腳底的震動探測細胞來察覺到地震信號?！?BR> What is clear from the Stanford team's earlier work with trained African elephants is that under ideal conditions, elephant infrasound calls can make seismic waves that can travel almost a mile and a half （two kilometers）.
在通過馴服的非洲象進行的較早的研究中，斯坦福大學研究小組已清楚：理想條件下，大象的次聲吼叫能使震波傳播兩公里左右。
The seismic signals are identical to the elephant calls in the air, says O'Connell-Rodwell.
地震信號和大象在空氣中的鳴叫是相同的，O'Connell-Rodwell說。
But are the elephants really picking up distant seismic calls through their feet?
但大象們真的通過腳接收了遠端的地震信號嗎？
"It seems evident from their behavior," said O'Connell-Rodwell.
“從它們的動作來看，這是很明顯的，”O(jiān)'Connell-Rodwell說。
Telltale behaviors that an elephant is listening to a call include standing very still and adjusting their ears, explained Payne.
Payne解釋泄密的動作是：大象在傾聽時，總是靜靜佇立，并且調整他們的耳朵。
But since infrasound in the air is known to travel much further then a mile and a half （two kilometers）, it's hard to be sure if elephants ever notice the seismic side of their calls or use them as a back up "line" on noisy days.
但因為次聲在空氣中傳播的距離要遠大于兩公里，所以很難斷定大象是否留意到了地震波的信息，還是只是在地表嘈雜的日子把它作為一條備份“專線”。
To sort that out, the Stanford team is now sending elephant calls through the ground only and watching the reactions of wild elephants to see if it catches their attention.
為了區(qū)分清楚，斯坦福的研究小組現在正通過只給大象發(fā)送地震波，然后通過觀察野生動物的反映來判斷他們是否留意到地震波傳遞的信息。
"We are now conducting seismic playback experiments in Etosha National Park, Namibia, that will tell us for sure if they detect the signals," said O'Connell-Rodwell.
O'Connell-Rodwell說：“我們目前在納米比亞的Etosha國家公園進行地震波回放實驗，很快就能確定它們是否察覺了信號。”
As for whether the ground can also get too noisy for seismic elephant songs, O'Connell-Rodwell says it's possible. Generators, vehicles and airplanes all can make a lot of seismic noise and can easily drown out elephant calls entirely.
談到地表是否會因為別的震波而影響了大象的聲音傳播，O'Connell-Rodwell說這是可能的。發(fā)電機、車輛、飛機都能制造大量的地震波，而且輕易就把大象的聲音完全蓋過。