What's the noise target of the Turboliner? In the 1990's Saab promised 76dB to Crossair but achieved only 78 dB, much to Crossair's annoyance.
I think good progress has been made in this area. The level, frequency & characteristics combined with new fluid dynamics technology has provided significant improvements.. e.g. the sharp wingtip transsonic noise seems almost eliminated.
YouTube - Airbus A400M TP400-D6 Engine Test
They should do some wotk on the starters though (or go for electric drive & start at a more remote place)..
YouTube - Fokker F27 Startup and Taxi