Verdecken der Schmalbandsprache durch Schmalbandrauschen
The masking of narrow-band-voice by narrow-band-noise
To study the influence of disturbing noise on the understanding of speech we cut the speech and the covering noise in single frequency-sections. The limiting range was 1/3 octave. Smaller frequency differences dit not allow understand even numbers. For speech and noise we used the same bands of 1/3 octave. Using a constant speech-spectrum the noise-spectrum was altered to lower and higher frequencies by steps of one third of an octave. We found, that the noise overlays more the higher frequencies. If the speechband is lower than the noiseband the effect of masking is one third of an octave at the maximum only. If the speech is higher, the masking includes on octave. If speech- and noise-band have the same spectrum the masking is not generally complete. Between 1250 and 2000 c.p.s. the disturbing influence is at the best only if the noise-band is lying 1/3 or 2/3 octaves lower than the speech.