Bluetooth audio circuit noise problem
After I provided a separate power supply through a separate onboard DC DC isolator the noise went away. Earlier I was trying to power the bluetooth module from the 3.3v voltage regulator of Teensy which was creating the noise problem. So bluetooth modules need a ground isolated power supply independently. Even if one takes a isolated power and send it through a voltage regulator of an arduino it will create problems. So a separate DC DC isolator is needed.