Clinical and Experimental Aspects of Phonetogram Analysis

A phonetogram is a diagram displaying sound pressure levels (SPL) of softest and loudest possible phonation over the entire fundamental frequency range (F0) of a voice.

Female singers mean phonetogram had a significantly higher upper contour than female nonsingers. When reading at various voice levels female singers produced markedly higher mean equivalent sound pressure levels (Leq) and mean relative F0 compared to nonsingers. During noise exposure the singers increased their mean relative F0 more than the nonsingers, but produced no difference in mean Leq.

Female singers used higher subglottal pressures than female nonsingers, which is a major factor underlying the difference in the upper phonetogram contour. The singers also attained higher SPL levels than expected from the subglottal pressure increase alone from softest to loudest phonation, a phenomenon that can probably be attributed to resonance effects.

After reading in noise for 15 minutes the lower phonetogram contour was raised for female and male dysphonic patients. Their upper contour remained unaffected. Neither contour was altered for respective normal speaking controls.

Female dysphonic patients displayed a lower upper phonetogram contour than female controls, with no difference in the lower contour. Male dysphonic patients did not differ from male controls in loudest phonation, but produced a higher lower contour in softest phonation.

When reading at gradually increased vocal loudness, female patients achieved higher levels after voice therapy, and raised their upper phonetogram contour. The male patients increased their fundamental frequencies less after treatment, and displayed a lowering of the lower phonetogram contour.