This paper reports about a female mutational falsetto, that means an unusual 
high (309 Hz base frequency) fundamental frequency of the speaking voice in a 
19-year-old girl. The psychological background and the epicrisis as well as the 
practical negative result of the hormon- and metabolism examination allow the 
diagnosis of this rare disturbance of the voice, the formal classification of 
which would on the other hand also allow the statement of a phononeurosis with a 
too high fundamental frequency of the speaking voice because the behavior of the 
voice from the menarche (12 years) up to the first examination does not seem 
assured definately. The individual median fundamental frequency of the speaking 
voice has inally been obtained at 270 Hz. Energy range of the speaking voice has 
been measured, glottography and sonagraphy has been carried out, all of which 
show the course of treatment clearly. It has been remarked critically that there 
has to be found a method to better reproduce the hearing impression in a figure. 
Investigations according to this have been made.