Effects of voiced consonants and speaker gender on the acoustic characteristics of preceding vowels in Ika
This article examines if the voicing of a consonant in Ika has any influence on the acoustic features of a preceding vowel. Ika (ISO 639-3 ikk) has nine vowels and this work centres on them. Nine pairs of words beginning with Ika vowels (the vowels preceding either voiced or voiceless consonants) were produced and analysed using the praat speech software. The acoustic characteristics (duration, fundamental frequency, first formant and second formant) of the initial vowels were investigated. Duration is measured in milliseconds (msec), fundamental frequency (F0), first formant (F1) and second formant (F2) are measured in hertz. The effects of voicing and speaker gender on these characteristics were observed. The results showed that the effects of voicing on the characteristics of the vowels were not statistically significant (p > 0.05). Although vowels preceding voiced consonants generally manifested longer durations and had lower F1 values, the ANOVA test conducted did not show significance at 5% probability. However, there were highly significant differences (p < 0.001) between the female and male speakers in the F0 and F1 values, with the female values being higher than the male values. Worthy of note is the result on the characteristics of the vowel /ɪ/ in voiced consonant environments as all the respondents (male and female) had equal values in all the acoustic characteristics analysed. This is an outstanding finding for an under studied language like Ika Igbo.