The COVID-19 pandemic triggered unprecedented environmental perturbations over broad areas, affording novel opportunities to measure outcomes of human-environment interactions. Here, I evaluate the response of a common songbird to noise pollution by comparing soundscapes and songs across the San Francisco Bay Area prior to, during, and after the Spring 2020 statewide shutdown. Restrictions on human movement during the shutdown reduced noise pollution, relaxing auditory pressures on animals such as birds that communicate via sound. Birds quickly responded to lower noise levels by producing higher performance songs at lower amplitudes, effectively increasing signal efficacy and salience. In contrast, song traits lagged increasing noise levels as restrictions on human movement loosened over time. Although song amplitude eventually returned to pre-pandemic levels, birds continue to produce high performance songs, with consequences for signal masking in noise. These findings indicate non-parallel behavioral responses to noise pollution removal and re-introduction. I discuss these differences in robustness and resilience in the context of a behavioral disturbance landscape, and implications of a regime change for signal function.