Connell's (2002) study of four African tone languages: Ibibio, Kunama, Mambila and Dschang reveals the existence of IF0 for Ibibio, Kunama, and Dschang.
We assumed the possibility that +ATR and--ATR behave differently with respect to IF0. Snider did find a nonsignificant effect in Chumburung, as mentioned in Connell (2002).
The F0 mean values of the vowels set the basis for assessing vowel height and vowel backness as patterns associated with IF0. These will be discussed in the following subsections.
There are positive IF0 values indicating a positive correlation between pitch and vowel height.
The F0 values for Female Speaker 1, in a high tone context, support Whalen & Levitt's (1995) claim that vowel backness is not a factor in IF0, but that /u/ has a tendency to have a higher F0 than /i/.
In a high tone context,--ATR vowels have greater IF0 with the exception of Female Speaker 2 while in a low tone context, +ATR vowels have greater IF0 with the exception of Female Speaker 1.
F0 values were measured at each vowel's onset and 20, 40, 60, 80 and 100 msec after this onset in order to determine if IF0 was more prominent at certain points than others.
In this paper, we addressed the issue of intrinsic pitch in Igbo, bearing on the general claim that IF0 is a universal phonetic effect (cf.