Using two-dimensional box plots to visualize the vowel space: A study of rounded vowel allophones in Tigrinya
Radu Craioveanu · Canadian acoustics · 2011
A study that was conducted to examine rounded vowel allophones in Tigrinya using two-dimensional box plots to visualize the vowel space is presented. A conventional box plot displays the median, interquartile range, and total distribution of the data along one axis. For bivariate data like formant plots, two box plots could be superimposed at right angles, but as these are computed for F1 and F2 separately, this is not entirely accurate. Tigrinya is an Ethio-Semitic language spoken in Eritrea and northern Ethiopia. It has received very little attention from a phonetic standpoint. As such, descriptions of two rounding processes in the language have only received an impressionistic description to date. A word list was prepared based on dictionary searches, comprising target words which would display VH or LVR. Sentences were devised to carry the target words, some composed by the author, others by the experimental participant. A decision was made not to use a consistent carrier phase.