An electroglottographic wavegram (short: EGG wavegram) is a tool for analyzing the voice source in speech and singing, based on electroglottographic (EGG) signals (and their first derivative, DEGG). [1]
The wavegram, invented by Christian T. Herbst, provides an intuitive means for quickly assessing vocal fold contact phenomena and their variation over time. Vocal fold closings and openings appear here as a sequence of events rather than single incidents, taking place over a certain period of time, and changing with pitch, loudness and register. Wavegrams document systematic phenomena[ clarification needed], indicating subtle changes of the vocal fold oscillatory regime.
Electroglottographic wavegrams are created in 5 steps (see illustration):
Wavegram data can be influenced by
Wavegrams show a potential to be used in:
To construct a wavegram, the time-varying fundamental frequency is calculated and consecutive individual glottal cycles are identified in the EGG or DEGG signal. Each cycle is locally normalized in duration and amplitude, the signal values are encoded by color intensity and the cycles are concatenated to display the entire phonation in a single image, much as in sound spectrography.
The idea of wavegrams can be extended to displaying other data, such as acoustic signals or high-speed video endoscopic recordings of the vibrating vocal folds. [3] [4]
An electroglottographic wavegram (short: EGG wavegram) is a tool for analyzing the voice source in speech and singing, based on electroglottographic (EGG) signals (and their first derivative, DEGG). [1]
The wavegram, invented by Christian T. Herbst, provides an intuitive means for quickly assessing vocal fold contact phenomena and their variation over time. Vocal fold closings and openings appear here as a sequence of events rather than single incidents, taking place over a certain period of time, and changing with pitch, loudness and register. Wavegrams document systematic phenomena[ clarification needed], indicating subtle changes of the vocal fold oscillatory regime.
Electroglottographic wavegrams are created in 5 steps (see illustration):
Wavegram data can be influenced by
Wavegrams show a potential to be used in:
To construct a wavegram, the time-varying fundamental frequency is calculated and consecutive individual glottal cycles are identified in the EGG or DEGG signal. Each cycle is locally normalized in duration and amplitude, the signal values are encoded by color intensity and the cycles are concatenated to display the entire phonation in a single image, much as in sound spectrography.
The idea of wavegrams can be extended to displaying other data, such as acoustic signals or high-speed video endoscopic recordings of the vibrating vocal folds. [3] [4]