Along with BlackBerry OS 10.2, BlackBerry introduced their Natural Sound technology for BBM Voice and BBM Video calls on all BlackBerry 10 smartphones. Natural Sound makes the promise that conversations will sound more natural and realistic and let you hear nuances and variations in tone, making it sound as though you're in the same room. 

Such things are hard to actually experience unless you've gone hands-on with it and have devices to compare directly with but BlackBerry has done their best in a video posted to the BlackBerry UK YouTube account. Even from the video clip, the difference is quite noticeable depending on what you listen to it on.