Animal Mimicry

You have an uncanny knack for mimicking animal sounds. If you are familiar with it, and a humanoid could conceivably reproduce it, you can make a good-enough impression that an untrained ear could not distinguish it. An expert (such as someone with the Sylvan Upbringing) could run an Intuition Check (or Knowledge if they have reason to suspect) to try to assess the veracity of the sound.