Make sure your Noise i1 and the mobile are within 10 meters range.

 If customer streams the music Online make sure the internet connection is stable

 Select the streaming quality to the maximum for better sound quality

Check for the streaming quality .

On mobile tap on the Music player

Tap Settings

Tap Streaming Quality

Select HD or the High

1. Distortion on  Music or calling : calling : Normal or Online : Normal call : Network issue

Wi-Fi calling off if still issue persist go for Reset and if not resolved go for RPU.

Music Online : Change network/ Wi-Fi and check still issue persist check streaming quality and Reset Post that if issue persist go for RPU.