Check out the difference between the Xbox 360 chat and the upcoming Xbox One chat in this article here.. It sounds so much clearer now. Nice to see an improvement in that area, it was needed!
Xbox One Delivers Premium Voice Quality via Hardware Improvements & Skype Codec:
http://www.xboxone-hq.com/news/63-xbox-one-delivers-premium-voice-quality-via-hardware-improvements-skype-codec