Education and Science, Disney's Animal Kingdom®, 1200 North Savannah Circle East, Bay Lake, Florida 32830, USA.
J Acoust Soc Am. 2011 Feb;129(2):1059-66. doi: 10.1121/1.3531798.
As in other mammals, there is evidence that the African elephant voice reflects affect intensity, but it is less clear if positive and negative affective states are differentially reflected in the voice. An acoustic comparison was made between African elephant "rumble" vocalizations produced in negative social contexts (dominance interactions), neutral social contexts (minimal social activity), and positive social contexts (affiliative interactions) by four adult females housed at Disney's Animal Kingdom®. Rumbles produced in the negative social context exhibited higher and more variable fundamental frequencies (F(0)) and amplitudes, longer durations, increased voice roughness, and higher first formant locations (F1), compared to the neutral social context. Rumbles produced in the positive social context exhibited similar shifts in most variables (F(0 )variation, amplitude, amplitude variation, duration, and F1), but the magnitude of response was generally less than that observed in the negative context. Voice roughness and F(0) observed in the positive social context remained similar to that observed in the neutral context. These results are most consistent with the vocal expression of affect intensity, in which the negative social context elicited higher intensity levels than the positive context, but differential vocal expression of positive and negative affect cannot be ruled out.
与其他哺乳动物一样，有证据表明非洲象的叫声反映了情感强度，但目前还不清楚积极和消极的情绪状态是否会在声音中有所不同地反映出来。通过对在迪士尼动物王国（Disney's Animal Kingdom®）饲养的四只成年雌性非洲象在消极社交环境（支配性互动）、中性社交环境（最小社交活动）和积极社交环境（亲和性互动）中产生的“隆隆声”进行声学比较。与中性社交环境相比，在消极社交环境中产生的隆隆声具有更高且更可变的基频（F0）和振幅、更长的持续时间、增加的语音粗糙度和更高的第一共振峰位置（F1）。在积极社交环境中产生的隆隆声在大多数变量（F0 变化、振幅、振幅变化、持续时间和 F1）中表现出类似的变化，但响应的幅度通常小于在消极环境中观察到的幅度。在积极社交环境中观察到的语音粗糙度和 F0 与在中性社交环境中观察到的相似。这些结果最符合情感强度的声音表达，其中消极社交环境比积极环境引起更高的强度水平，但不能排除积极和消极情感的不同声音表达。
