[Practical significance of measuring high formant spectra in phoniatric voice assessment]

The measurement of sound energy in the spectral region between 2 and 5 kHz provides additional information to the auditive assessment of voice quality. It can be applied to healthy an sick voices, e. g. in tracing the therapeutic course. Devices for measuring voice range profiles with the possibility of evaluating the high formant region are especially useful and valuable. But, nonetheless, simultaneous auditive assessment is crucial to avoid misinterpretation. Calculation of the quotient of the sound pressure level in the region between 2 and 5 kHz by the total sound pressure level allows to determine vocal sound characteristics and changes of the sound. Pre- and postoperative sound spectra obtained from the voices of patients with diseases of the vocal folds illustrate the improvement of the harmonic structure and the decrease of noise components. The measurement of the high formant intensity has proven to be appropriate for the registration of the voice quality before and after therapy in 130 cases. Although the value of these measurements is highly validated in the phoniatric practice, extensive studies and, especially, expert discussions are still needed. The authors come to terms with opinions that question the validity of the described methods.