In music, vibrato describes the warble effect often added in by singers as they sing. I was trying to come up with a circuit to remove it from an audio signal, almost like a "vocal stabilizer" leaving only the pure vocals and I'm a bit stuck. My first thought was that there are a few characteristics of vibrato that differentiate it from the rest of the signal. Most of my knowledge of audio circuitry is self-taught, so please excuse my lack of proper terminology. Vibrato tends to be:
One relatively-regular low frequency (~2-20Hz) overlaid upon the existing "note frequency" (the 80Hz-15kHz normal range of human voice determining note in the music)
Oscillation of both amplitude and frequency, sharing the same interval. I.e. in vibrato both the volume and note go up and down simultaneously, at that same 2-20Hz
Infrequent, only appearing on certain parts of the signal (by time)
It would seem based on these three characteristics that vibrato is definitely differentiable, it's just difficult to extract without removing other detail. Any ideas?