Rapidly changing environments impose novel selection pressures on organisms, and sometimes adaptive phenotypic plasticity allows organisms to survive and reproduce in the face of environmental change. However, plastic responses can also be maladaptive. In this study, we investigate whether male reproductive investment responds plastically to varied experience with traffic noise. We exposed male crickets chronically to one of three noise treatments from the 2^nd-3^rdinstar until their natural death: masking traffic noise (including noise that overlaps in frequency with the male crickets’ mating calls), non-masking traffic noise (an identical traffic noise track from which we digitally removed the frequencies that mask the crickets’ mating call), and silence. We dissected and weighed their testes and spermatophore molds. Controlling for body mass, we found that the spermatophore molds of crickets reared in masking and non-masking noise were 29% and 24% lighter, respectively, than those of crickets reared in silence There were no differences in body mass adjusted testes mass among treatments. If spermatophore mold mass is positively associated with male reproductive output, this reduction in size could have negative fitness consequences for animals exposed to traffic noise. We encourage future work to investigate impacts of noise on reproductive investment in other study systems that are likely sensitive to anthropogenic noise (e.g., birds, frogs, singing insects).