You’ve probably been mesmerized by the fluid, flamboyant and finesse Luo accent 😉 – popularly identified by the elongation of vowels and the legendary switching of ‘sh’ with an ‘s’ . A recent research study may provide an explanation to this immaculate accent 😀 . In a concept referred to as Acoustic Adaptation, researchers Ian Maddieson and Christophe Coupe devised a hypothesis that explains how human language has been shaped by climate and terrain.
In the research, correlation analysis was conducted on phonological patterns and measures of temperature, precipitation, vegetation, and geomorphology, and through it discovered that denser vegetation or higher ambient temperatures favored greater use of sounds characterized by lower frequencies. Among the Luo sub-tribes, only the Kenyan dialect, and the Ugandan Adhola show evidence of using low-frequency vowels. The map below overlays vegetation cover and migration path of the Luo.
An interesting pattern emerges from the map. The vowel elongation among the Adhola and Luo seems to have developed after crossing/interacting with Mount Elgon and Kakamega forest on the migration path. According to the acoustic adaptation hypothesis, humans switch to low-frequency sounds in forested areas due to the hindrance of propagation of high-frequency sounds by obstacles. It suffices that pronunciation of ‘sh’ requires a high pitch and thus words borrowed from the neighboring Bantu tribes were rendered with an ‘s’ to maintain low pitch.
The elongation of vowels also converts a high pitched word to low pitch. A good example is the word ‘Myer’ and ‘Mier’ which means village in Acholi and Luo respectively. The former utilizes letter ‘y’ to emphasize sharpness while the latter uses an ‘i’ to prolong pronunciation. Other examples include ‘Nykaw’ and ‘Nyikwa’ that mean grandchildren in the Anuak and Luo respectively. Note the introduction of an ‘i’ and exchange of ‘k’ and ‘a’ to induce an elongated pronunciation.
Gerrit Jan Dimmendaal notes in his book ‘Historical Linguistics and the Comparative Study of African Languages’ that:
In Luo, there is a set of preverbal tense markers which are absent in closely related varieties such as Alur, Lango, or Acholi. Moreover, no comparable tense marking system is found in other Western Nilotic groups (the sub-branch of Nilotic to which these languages belong), i.e in Northern Lwoo, Dinka-Nuer, or the Burun, as far as present knowledge goes.
He concludes that the Luo system of language must constitute an innovation – the development of a system of verbal tense making. He attributes this to shift-induced interference in which one tribe/language switches the use of vowels in order to make themselves easily understood by another tribe – in this case, neighboring Bantu tribes (Gusii especially).
This theory is entirely plausible. However, subtle differences in pronunciation within the Kenya Luo lends weight to the environment argument. The word ‘Siro’ (Market) is rendered as ‘Chiro’ in South Nyanza, a region of less vegetation cover compared to Central Nyanza (Siaya). Given all Luos initially lived in Central Nyanza and only crossed to the lake in 1700s, it is safe to deduce that Acoustic Adaptation had a role in switching their accent.