The family keeps in constant contact with whispered calls. 一家人会通过轻声低语保持联系

144. In this nursery bay, there are plenty of playmates.
     在这片育婴海湾中 能找到很多玩伴
145. But a mother never lets her calf stray too far...
     但母亲不会让幼鲸跑得太远
146. ..and will always offer a welcome embrace.
     并总会提供一个欢迎的拥抱
147. The family keeps in constant contact with whispered calls.
     一家人会通过轻声低语保持联系
148. New research has revealed
     最新的研究表明
149. that in shallow coastal waters, their calls not only fade quickly,
     在沿海浅水区 它们的声音不仅会迅速消失
150. but are also concealed by the sound of waves breaking on the shore...
     而且会被海浪拍击海岸的声音掩盖

来自《行星地球 第三季 第一集 Planet Earth S03E01 海岸》第 147 行