Effect of additive interference on speech transmission

This paper presents the relationship between logatom
intelligibility of Polish speech and a level of masking random noise. Subjective
measurements of intelligibility were carried out for optimal speech signal level
85 dBA and signal to noise ratio within a range from -15 dBA to +15 dBA. The
influence of the frequency distortion (band limiting) was investigated for three
cases of a band with: 100-6000 Hz, 400-2500 Hz and 300-3400 Hz. The obtained
results are shown as a curve describing a relation between a logatom
intelligibility and signal to noise ratio (S/N). The obtained characteristics
were compared with a standard curve given in ISO Recommendation for a two-ears
listening test.