Noise mapping is based on long-term noise indicators, such as L _N or L _DEN. On the other hand, transportation intensity changes during a day (road traffic peak hours) or a year (more flights during holidays) and this variability is not reflected in single sound level values. We wanted to find out whether not only sound level but also the number of noise events is the factor influencing noise annoyance assessment. Ambisonic recordings of real traffic in a city were used. Road, tramway, and aircraft traffic were investigated and two factors were manipulated: the equivalent sound level value and the number of noise events. All stimuli were presented in an anechoic chamber. The results showed that sound level is always a statistically significant parameter while the number of events has an impact only for tramways and airplanes. Moreover, the difference is observed only between one or more subgroups, no matter what the sound level value was. For road traffic this relation was not found to be statistically significant. It was also shown that the existence of tramway bonus or airplane malus is linked with the number of noise events.

The aim of the study was to examine how the wording of a question about audio, visual and audiovisual stimuli can affect the assessment of the environment. The participants of the psychophysical experiments were asked to rate, on a numerical scale, audio and visual information both separately and together, combined into mixes. A set of questions was used for all the investigated audio, visual, and audio-visual stimuli. The participants were asked about the comfort or the discomfort caused by the perceived stimuli presented at three different sound levels.
The results show that there are no statistically significant differences between the assessment of comfort and discomfort associated with visual samples. Actually, the comfort and discomfort ratings are equivalent to the extent that a discomfort rating can be represented as the opposite to the comfort rating, i.e. the discomfort rating is equal to the 10 minus comfort rating.
In general, the results obtained for audio and audio-visual samples were the same, with only a few exceptions that were dependent on sound level. No statistically significant differences were found for the loudest stimuli, but there were some exceptions for the softener cases. Based on the results, we show that only for visual stimuli both scales are totally interchangeable. When presenting audio and audio-visual samples, only one scale should be applied – either discomfort or comfort, depending on the context and the character of the stimuli.