By measuring the vocal penetration a characteristic feature of the eff
iciency is covered which is essential for all three parts of the commu
nication chain of speech with special emphasis on the percipient. Resu
lts are expressed in decibel (AS) of a defined masking noise, at which
50% of the logatomes spoken by the test persons are recognized. The v
ocal efficiency is indicated by the sound pressure of the masking nois
e, subtracting the sound level of speech used. Individuals with a heal
thy voice lie within the range of 12-24 dB (AS), average value 20 dB(A
S), patients affected with a vocal disorder lie within the range of 0-
12 dB(AS), average value 9 dB(AS). The vocal penetration significantly
correlates with the auditive features of the vocal swinging-in phase;
it proves to be a sensitive indicator of treatment efficacy for dysph
onia and a useful tool for predicting the vocal capacity in all voice
professions.