Although it's not really related to the sound of the RBR or the traction control debate, Mercedes have said they think RedBull and more recently Lotus (the top two Renault powered teams) have had some clever engine mapping tweaks form Renault that have given them some significant advantages

Mercedes aims to uncover and match Renault engine mapping trickery | Grand Prix 247

Also some more interesting things on the engine sound and the unlikeliness that it is traction control

http://grandprix247.com/2013/10/01/i...ttels-success/