Vanotsvakurudza vanoshandisa hydrophones (kazhinji dzakashandurwa kubva kumashandisirwo avo ehondo ekutanga mukutevera ngarava dzepasi) kuti vaone nzvimbo chaiyo inobva mhere mhere. Nzira dzavo dzinovabvumirawo kuona kuti kure zvakadini kuburikidza negungwa ruzha rwunofamba. Kutsvakurudza kwakaitwa naDr. Christopher Clark weCornell University achishandisa dheta rehondo kwakaratidza kuti mhere mhere dzinofamba kwezviuru zvemakiromita. Kunze kwekupa ruzivo nezvekugadzirwa kwenziyo, iyo data inobvumira vatsvakurudzi kuti vatevere nzira yekufamba kwehove mukati me "kuimba" (kubereka) mwaka. Chimwe chinhu chinokosha ndechokuti hove, mune imwe nzira inonzi Lombard effect, inogadzirisa rwiyo rwavo kuti dzibhadhare kusvibiswa kwemhepo. Uyezve, pane uchapupu hwokuti hove dzemazuva dzinorega kubudisa D kudana mid-frequency sonar, kunyange zvazvo imwe nguva mid-frequency sonar inoshandiswa, kunyange zvazvo nguva yepakati (1<unk>8Hz) inodarika makumi matatu nguva imwe neimwe inofamba.
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