echo hatchback noise at the front

[echohatchback2005]

hi, just wondering if you guys know what is problem of my echo hatchback.(manual tranny)
The symptoms are:
Whining noise and humming noise coming from the front middle part of the car (more noticeable when turn left or right) . a bit vibration that I can feel it from my steering wheel and floor. Speed sensitive after 50 km/h. The faster it go, the noisier I can hear. Noise still present when I shift to neutral while the speed still at 80 km/h ,so i dont think is the problem of the input or output shaft of the tranny. Last month I changed the wheel bearing and the noise is gone for 2 weeks. But after the 2 wheeks the noise is come back again. I try to use a mechanics stethoscope and listen the noise but I cannot find out when it come from. So now i start thinking is the CV shaft or the differential ring gear.
Hope someone can help me. thx alot.

[JNEG]

Sounds like a CV joint on it's way out to me, especially because the noise increases while turning, but I'm not a mechanic.

[echohatchback2005]

Yes, but there is no knocking noise, Some mechanic say maybe is the diff. I can easy go to junk yard and get a tanny, but I just want to know what is wrong before i go ahead and spend 400 dollar for a used one. What is the normal diff. noise when it is broken?

[soloecho2]

Did you replace one or both wheel bearings ? My first went at 120,000 KM second went at 165,000 KM.