1996 Volvo 850

Hello and thanks for donating

Most likely a foreign object has stuck in the tire tread, especially if the sound is constant regardless of wheel position and is louder outside the window than inside the vehicle. Check all tire treads.

Second most likely if front wheel drive is rezeppa, or tripoid type constant velosity (CV) joint. That's the shaft which transfers your engines torque to the wheels. However, the sound is only while turning right or left which puts stress on the shafts pivit points. To check this, go to a large quiet lot and drive in slow sharp circles left and listen for sound, then right listen for sound. If you hear a click left, replace left front CV axle, if right then right front CV axle replacement.