Carolyn Schwartz

San Francisco State University

“Coping with city noise: Assessing environmental noise and hearing abilities along an urban-rural gradient”

My research examines variations in environmental noise levels and hearing abilities among Pacific chorus frog populations in urban and rural areas across the San Francisco Bay Area. This is the first study to examine the physical properties of noise in the environment and its potential effects on hearing abilities.


Anthropogenic noise (human-generated noise) has increased to unprecedented levels and is considered a hazardous form of pollution. This pollutant alters the acoustic environment and has been observed to negatively impact species that communicate acoustically. Many studies have examined how acoustic communication signals change to counteract the detrimental effects of anthropogenic noise. However, we know little about the physical properties of the noise and whether hearing abilities also change in response to human-generated noise. Using populations of Pacific chorus frogs (Hyliola regilla) across an urban-rural gradient in the San Francisco Bay area, I am examining variation in (1) environmental noise levels and (2) the ability of the auditory system to detect signals in noise. Initial analyses of environmental noise levels display temporal variation across frequencies of 0.5 to 4.0 kHz. Between populations, my results show minor differences in hearing abilities in noise. This is one of the first studies to provide a detailed characterization of this novel pollutant and its potential effects on hearing abilities.

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