密歇根新闻广播 研究表明鸟鸣声也许能增加你的安全感（在线收听）

Walking through an empty parking structure or some public place that isn't crowded or well-lit can inspire the imagination and bring on a case of the creeps.

It can make people feel the place is unsafe, even when there's no evidence.

University of Michigan marketing professor Aradhna Krishna wanted to figure out if the right mix of sounds can make us feel safe.

Krishna is the director of the Sensory Marketing Lab at the Ross School of Business, and says they've been conducting a study on the effects that sound has on our perception of safety.

In a field study at a parking garage, Krishna says they played different types of sounds that they suspected might alter the way the space is perceived.

"Our hypothesis going in was that certain kinds of vocal sounds … would create a feeling of safety," she says.

Krishna says they chose bird sounds because of the similarity they share to human vocal sounds both, "in their melody and in their language."

She explains they were thinking that bird sounds within the stairwells of the parking structure might create a sense of social presence which would in turn create a perception of safety.

As controls, Krishna says they tested using conditions of silence and of music that was similar to the bird sounds in tone and tempo.

"Indeed, the bird sounds created a higher sense of safety," she tells us.

The experiment was recreated using conditions of human vocal sounds, classical music and silence. According to Krishna, while the human sounds did score a little higher than the bird sounds, both performed much better than either music or silence in terms of creating a sense of safety.

Krishna says they conducted other experiments for which they created videos shot from a first person perspective of a person walking through a parking garage or through a subway station.

They showed these videos to people, and by changing the background music, Krishna says they were able to observe a notable difference both in perception of safety and willingness to purchase a subway pass.

So background sound and music can indeed change the way we perceive the space around us, according to Krishna, at least as far as safety goes.

She says the takeaway is twofold.

"Firstly, we would advocate using vocal music in places which were indeed safe already, and you wanted to make people realize that these were safe," Krishna says.

"But on the other hand we do not want people to use vocal sounds in areas that are indeed unsafe to create this false perception of safety. So you have to use these results in a very careful way."

-Ryan Grimes, Stateside