 The speed of the vibrato often has a great effect on the way the note is perceived, with faster vibratos commonly adding tension and stress, while slower vibratos produce a more lyrical sound.The slowest of vibratos can be used to imitate a bowed instrument "growing" a note after its initial inception.Even though this effect refers to volume in bowed instruments, having a pitch variation that follows the same structure of the volume variation in many situations can have the same effect for the listeners.