Table 1.

Definitions of measures of human infant crying.

TEMPORAL
Latency	Duration (s) from stimulus application to onset of first expiratory cry sound
Expiration duration	Duration (s) of each individual expiratory component
Inter-cry-interval	Duration (s) from offset of one expiratory component to onset of next expiratory component
SPECTRAL
Peak F0	Fundamental frequency (Hz), measured at its highest point in each expiratory component of the recorded cry bout
Amplitude of peak F0	Amplitude (relative dB) of Peak F0
Dominant frequency	Frequency (Hz) of harmonic with highest power (amplitude); measurement obtained from power spectrum at point of Peak F0
Amplitude of dominant frequency	Amplitude (relative dB) of dominant frequency
Overall maximum amplitude	Highest amplitude (relative dB) sound found in each expiratory component
ACOUSTIC STRUCTURE
Dysphonation	Rating of percent of expiratory cry component that is not periodic due to sonic turbulence; measurement obtained from spectrogram
Hyperphonation	Peak F0 above 1000 Hz due to qualitative shift in frequency