An update on horn-based vehicle signaling, and newer sound effects for convenience, nostalgia, and entertainment

A presentation at the 2013 International Congress on Acoustics explored vehicle horn-based lock alert use and the conflicts it created among neighbors. From 2007 to 2012, more than 60% of vehicles manufactured for the North American market left factories with horn-based alerts to signal locking and unlocking. Most were set to honk at the second press of the key fob’s lock button, although settings could be changed to flashing lights or no audible or visual alert. Automakers addressed questions about legality in user manuals, stating that owners should observe local laws. By 2013, internal combustion engine vehicles had become quieter, and electric and hybrid vehicles seemed to offer a chance to reduce noise further. Instead, automakers adopted horn-based features in electric and hybrid vehicles, and added sounds for convenience, nostalgia, and entertainment, using external speakers. Reviewing auto industry data, noise ordinances, federal, state, and local regulations, and case law, we examine legal and regulatory aspects of non-emergency horn signals and vehicle sound effects.