音响航标 meaning in English

audible navigation signal
audible signal

According to the " the history of aids to navigation in china " , aton in shanghai harbor has been developmented for long tiome ago rapidly . when establishing international shipping centre was determined on the 21 centry in shanghai harbor . aton must be faced to new challenge and it also be required to meet to the needs of the times
随着航标从“基石立标” 、塔标、音响航标、视觉航标到目前的无线电航标、数字化航标的演变，充分反映了其与上海港航运事业同步发展的密切关系。当上海确立了21世纪建立国际航运中心的发展战略后，航标也必然会面对新的挑战，被要求与国际航运中心的地位和需求相适应。