Noise Reduction:I own a 2018 MacBook Air. Apple and several other laptop manufacturers make decent machines with great components and in most cases noise is not an issue. However, my laptop has always had a rather noisy USB C port (specifically the second one from the top) most likely unit specific as I have used my plug and play dongle dacs on other systems and not experienced the same level of fatigue as I would on mine due to what I presume is low level noise that over time made long session’s impossible. Further more, (and I want to specify that this may just be in my unit and not other MacBook Air models) but there would be moments when during heavy use of several apps; Apple music, Adobe Apps, IMovie.. I’d almost hear my laptop chugging bits through my dongle dac and through my earphones. The Dac in question is a Radstone Hud100. Low level Noise, the then-induced fatigue and the wild beeps and boops ceased to exist when I plugged in this guy. It’s actually pretty incredible! ( I do think it’s time I get a new laptop though..)Sound Quality:Music sounds more cavernous. Well spaced. Layering is somewhat enhanced. Then again most of that depends on your system but the iSilencer somehow acts like windex to the glass pane that is your system and earphones/headphones. Tracks sound, to me atleast, almost 30-40% more transparent. The change in experience is noticeable, almost immediately. Bass is defined better, reaches deeper. Mids are more present (maybe a touch brighter). Treble doesn’t change much but “air” is what I feel can be detected better. My enjoyment of music has increased since I got this thing and at the end of the day that’s what I want to pass on and hope you get from this device, again, if it fits your use case…Great stuff Ifi team. LWYLT.