If the turbo noise is just a hiss then nothing at all to worry about - maybe you've just become aware of it.
Check all the intake hoses and joints for security and integrity.
If you're turbo has failed you'd have a massive loss of torque and power. The car would be virtually undriveable.
Try a decent fuel additive firstly - see if that clears the EGR PCV - it could simply be that excess exhaust gas is being recycled into the intake tract.
Forte Gas Treatment is high recommended. Stick the whole bottle in the tank. Now fill with decent petrol (Esso, BP etc. not supermarket).
Check oil level is OK and all other service items are up to date, then go for a drive. Let engine warm up normally and then give it some therapy
Hold on to lower gears, trying using 2nd all the way to the red line and keep it at that speed for a minute or two.
Get third and drive again round to the red line.
Half an hour or so of firm driving can cure all manner of ills.
Do, of course, pay full attention to the road whilst doing this. Don't go taking needless risks.