A police officer's tone reveals a lot about racial disparities in policing.

That's what researchers found in a series of experiments where they played 250 audio clips of police stops to 414 people of varying races and genders.

The researchers edited the clips, which were split evenly between Black and white male drivers, so participants couldn't understand what an officer said but could still hear their tone. Researchers kept officers' race and gender secret, but it's possible participants could still infer some of those details from the audio, says Nicholas Camp, lead author on the study and assistant professor of organizational studies at the University of Michigan. The driver's speech was also omitted so participants only heard the officers' tones.

Even so, participants in the study published this week in the Journal of Personality and Social Psychology rated police officers' tones when talking with Black male drivers as significantly less friendly and less at ease than with white male drivers. These results held true despite participant and officer demographics.

Read the full article at Mashable.