Nissan Motors Co would be the world's first hybrid to come equipped with standard pedestrian warning sounds for its new 2012 Infiniti M35h, when it goes on sale at Infiniti retailers nationwide in early 2011, the carmaker said in a statement.  

The new audible warning system, called Approaching Vehicle Sound for Pedestrians (VSP), uses a range of distinctive sounds to help ensure the safety of other road users, the statement said.

The Infiniti M35h can travel at speeds of up to 62 miles per hour on engine noise-free electric power alone, road noise past approximately 20 miles per hour means the vehicle generates sufficient sound for the VSP to remain off, it said.

Other hybrid carmakers are also moving in similar directions, anticipating a new regulatory frame work, to be in place in few months.

With major automobile companies in United States going full throttle to launch a slew of electric cars in coming days and Nissan Leaf and GM's Chevrolet Volt to hit roads in few weeks, lawmakers are concerned about the new developments and trying to find a solution.

Last month, researchers at Warwick University's WMG (formerly Warwick Manufacturing Group) had built electric van called ELVIN (Electric Vehicle with Interactive Noise) to find out what noises alert pedestrians efficiently and yet do not annoy them.

Electric Vehicles are very quiet externally and internally, which makes them a potential low-speed safety risk to pedestrians. Sound not only alerts people to the presence and direction of a vehicle, it also indicates the type of vehicle -- for instance a bus -- and whether it is stopping or accelerating, the lead researcher on the project, Professor Paul Jennings from WMG at the University of Warwick said on the university website.

A bill -- Pedestrian Safety Enhancement Act of 2009 -- is currently at committee stage in the U.S. Congress, examining whether there is a need for minimum sound levels on motor vehicles. The European Union is also considering a similar legislation.

The bill seeks to provide ways or means of alerting blind and other pedestrians of approaching motor vehicles and alert them.