Glottal Area Waveform Measurements for Healthy Female and Male Speakers in Typical, High-Frequency, and Soft Phonation.

Only healthy young adults were studied, so these data say nothing about older adults, children, or people with voice disorders. The sample was not balanced or sized to test differences between men and women; the authors state the study was not designed to examine sex effects. Participants chose their own pitch and loudness rather than matching a target, which the authors say may add variability between speakers. High-speed video is two-dimensional, so it cannot measure how far the vocal folds move vertically, how the mucosal wave travels sideways, or the true amplitude of vibration. The muscle explanations, such as cricothyroid activity and subglottal pressure, are inferred from the shape of the waveform rather than measured, because no electromyography or pressure recording was done. 22 of the 92 recruited participants could not complete all three tasks because of a strong gag reflex, and no sample size calculation was performed in advance.

The work was funded by the National Institute on Deafness and Other Communication Disorders and the Deutsche Forschungsgemeinschaft (German Research Foundation). No other funding source or competing interest is declared in the paper.

Do not read these values as normal ranges for your patients. They come from 66 healthy young adults who chose their own pitch and loudness, and no sample size calculation was done, so a single patient's numbers should not be called abnormal by comparison with them.