Accuracy and reliability of formant frequency measurements in infant CV-like utterances
Raymond G. Daniloff, Nancye C. Roussel, Creighton J. Miller · The Journal of the Acoustical Society of America · 1989
The accuracy and reliability of measurements of infant formant frequencies were investigated. A total of 40 CV-type tokens (C = labial- or velarlike stop closant, V = /i/-like or /ɛ-like vocalic segment) were selected from recordings of vocalizations of two infants, ages 2–4 months. The tokens were of good acoustic quality and were taken from recordings of postfeeding mother-child interactions. Formant frequency measurements were made from both single FIT cross sections using a 10-ms sampling window and averaged, time-advanced, spectra. Time-advanced FFTs were computed using three successive FFTs taken at 2.5-ms rightward shifts of the 10-ms window. Three investigators independently measured formant frequencies in all tokens. Wideband 500-Hz spectrograms of each token were used to establish baseline values of formant frequencies for comparison with measured FFT values. Inter- and intraobserver reliability was also determined.