Q: my music pause randomly, and i can't hear anything from speaker excpt ringtone

If you have tried all the steps mentioned in this article Troubleshooting iPhone hardware , you'll have to get your phone checked by Apple or an Authorized Apple Service Provider.

Acoustic-speaker/microphone/receiver

Get help with these issues:

• No sound or distorted sound from speaker
• Microphone issues
• Receiver issues
• No sound through stereo headset

Are you using the headphones that came with the phone?

Did you try another pair of headphones?

If other headphones do not work as well, this might be hardware related and the phone has to be checked.

One more ting to try before you'll have to get it checked, set it up as new device without using the latest backup. This way you can rule out a software issue, in case your backup contained damaged data. If this does not work either, this is hardware related and the phone has to be repaired.

How to erase your iOS device and then set it up as a new device or restore it from backups

You're welcome, Good Luck.