Breathy Voice
Breathy voice is typically associated with a reduction in acoustic intensity and a lowering of fundamental frequency relative to modal voice. In addition, breathy voice is marked by the presence of substantial a periodic or noisy energy in the signal, unlike modal and creaky voice. The leakage of air through the partially open glottis widens the bandwidth of individual formants, thereby obscuring formant structure. The combination of poorly defined formant structure and increased turbulence reduces the definition and complexity of individual pitch periods observed in waveforms of breathy vowels. These characteristics of breathy voice can be seen in the spectrogram.
Breathy voice is also associated with spectral characteristics which differentiate it from modal voice as well as from creaky voice. Breathy voice characteristically displays the greatest decrease in intensity of spectral components at higher frequencies. Thus, breathy voice occupies one end of a continuum of spectral tilt with creaky voice at the other extreme and modal voice occupying an intermediate position. Low frequency components are relatively weak for creaky voice compared to modal voice. Low frequency components in breathy vowels are conversely relatively intense compared to modal voice (Attinger, Segal, 1959).
Spectrogram
A spectrogram, like a musical score, is a visual representation of sound. As in musical notation, the horizontal dimension corresponds to time (reading from left to right), and the vertical dimension corresponds to frequency (or pitch), with higher sounds shown higher on the display. Frequency is measured in Hertz (Hz), or cycles per second; and in kilohertz (kHz) or thousands of cycles per second. The relative intensity of the sound at any particular time and frequency is indicated by the darkness of the spectrogram at that point (Kayter, 1997)......
