Compared to a turbocharged unit like a GP40 or F40PH, GP38-2's will make a more vocal sound (because of a more open exhaust system), but not as deep (because of a lower horsepower rating). I recall the ex-LIRR units that passed where I live (on St. Lawrence & Atlantic) sounding quite "healthy", probably since they were all freshly rebuilt for LLPX leasing. They also did sound a bit louder than the GP40M-3's currently used--mainly because the trains back then had 4 GP38-2's instead of 2 GP40M-3's with slugs now!