This paper discovers methods to create vibrato effects with artificial reverberation. Feedback delay networks have been used for many reverb effects. Past work with time varying feedback delay networks has focused primarily on small modulations of the delays and or feedback matrices in order to create a more natural sounding reverb. In this paper, we consider the possibility of using wider modulations of these reverbs for the purposes of sound effect generation. Specifically, amplitude modulation and frequency modulation can be obtained by varying feedback matrices or delay lines respectively. The results showed a convincing vibrato effect with minor artifacts and promise for using FDNs in sound effect generation. Future work will include reducing artifacts and fine tuning control parameters.