Table 1.
Factorial design of the listening experiment with acoustical stimuli of different spectral shapes (low-frequency (LF), wind turbine (WT), pink), depth of periodic amplitude modulation (AM, expressed as standard deviation (σpAM) of the periodic level fluctuations), and occurrence or absence of random AM (with, no). The table shows the number of stimuli per variable combination. Except for two stimuli (cf. footnote 1), the stimuli were reproduced at a LAeq of 40 dBA.
| Depth of Periodic AM | Spectral Shape | |||||||
|---|---|---|---|---|---|---|---|---|
| LF | WT | Pink | ||||||
| Random AM | ||||||||
| with | no | with | no | with | no | |||
| σpAM = 0.0 dB | 1 | 1 | 3 1 | 1 | 1 | 1 2 | ||
| σpAM = 1.5 dB | 1 | 1 | 1 | 1 | 1 | 1 | ||
| σpAM = 3.0 dB | 1 | 1 | 1 | 1 | 1 | 1 | ||
1 reference stimulus, additionally reproduced at a LAeq of 37 and 43 dBA, besides 40 dBA. 2 pink noise.