it was demonstrated that what you are doing with your hands may affect what you hear, or at least how quickly you hear it.
In essence, subjects were instructed to respond by touching a button when they detected a heavily embedded background sound, either with their right or left hand. Right handed response was better at detecting fast-changing sounds; the left, better at slow changing sounds, according to Turkeltaub, " . . . the left hemisphere likes rapidly changing sounds, such as consonants, and the right hemisphere likes slowly changing sounds, such as syllables or intonation . . . " Well, maybe . . .
The study at least further establishes the potential connection between haptic work and L2 sound change. In this case, when the learner performs a PMP, mirroring the model and listening to the model of the target sound--without overt speaking--anchoring should be enhanced, more efficient. Part of the reason for that, as reported in several pervious posts, is that "fast" sounds tend to be in the right visual field (attached to the left hemisphere) and "slower" sounds, the left.
Keep in touch! (v2.0 will be released next week!)