This is an interesting article from the Vancouver Sun regarding the recent move by the Canadian Intellectual Property Office (CIPO) to allow the trademarking of sounds: http://www.vancouversun.com/technology/Sounds+that+send+message/6490368/story.html?goback=.gde_726837_member_109465483

When I was working on the concept audio for the Chevy Volt, there was a tremendous amount of thought and discussion that went into the emotional impact that the sounds within the vehicle would have on the driver. They wanted to convey the power of the Volt, but at the same time make it feel welcoming and not agressive. They also wanted to highlight the green technology of the car. I experimented with synthetic and natural sounds like water and wind to zero in on the tones that best suited what they described. I recorded spinning magnets, my breath through a conch shell, and a plucked cello and layered them together for one cue. The whole project was an interesting challange and a fun process. I’m glad to see that CIPO is taking audio trademarks into consideration and I hope it means that more companies will consider audio branding.