An interview with prof. Anna Preis, Departament of Environmental Acoustics, Institute of Acoustics, Adam Mickiewicz University in Poznań, Poland.
You presented at Internoise 2010 a paper entitled “Speech intelligibility as an annoyance index”. What’s the reason of such idea?
– Noise annoyance is very subjective matter and individual estimations can vary a lot depending on mood or personal tolerance to noise of subjects. Moreover…
noise annoyance strongly depends on one’s activity. The same noise can be estimated as a …, more or less annoying. How does someone estimate the same noise during rest and when trying to communicate?
How did you carry out your experiment?
– We prepared a series of tests of speech comprehension in noise. Subjects had to cope with nine different types of distracting sounds trying to understand a sentence matrix test presented at constant level of 61 dBA. Distracting noise level was variable depending on subjects’ difficulties in comprehesion.
What’s your conclusion?
– Experiment shows that during communication type of distracting noise is important for its annoyance. In our test, speech comprehesion on the level of 50% was possible under train noise of LAeqT = 86 dB. When noise sample was changed from train to babble, similar level of comprehension was possible only to level of LAeqT = 68,8 dB.
Results show that noise annoyance ranking of the noises by using the speech intelligibility scores are similar to the ranking used in field studies. However, there is a large difference between the noise annoyance ratings obtained in a field studies and speech reception threshold obtained for these nine noises. While in noise annoyance ratings collected in field studies there are large interindividual differences among participants’ annoyance judgments when it comes to speech intelligibility scores participants agree very well in their judgments.