Estimation of reaction time for birdsongs and effects of background noise and listener?s age

Recordings of birdsong are often used as an auditory signal for visually-challenged people in public spaces in Japan. To examine the detectability of these sounds, we measured reaction times (RTs) for six types of birdsong: Jay, Cuckoo, Himalayan cuckoo, Japanese grosbeak, Japanese white-eye, and Japanese bush warbler. We presented birdsong stimuli with irregular timing to 20 younger and 20 older participants in combination with silence, white noise, or bandpass noise with a center frequency of 1, 2, or 4 kHz. Regardless of the output levels and participant age, the RT for the Jay, Cuckoo, and Himalayan cuckoo songs was lower than 0.75 sec in the silent condition, and the averaged RT obtained by the younger participants could be estimated on the basis of the duration required to reach a specified sound exposure level for the birdsong stimuli. In the noisy conditions, spectral masking via bandpass noise prolonged the RT, while the bandpass noise with a center frequency higher than that of the birdsong tended to shorten the RT, especially in older participants. (c) 2022 Elsevier Ltd. All rights reserved.