I did this stuff a little while back, I think the dose was 80mg, but the brief TR I wrote has disappeared so I can't be sure.
It really was remarkable to do a primarily auditory hallucinogen. I felt relatively normal, and things looked relatively normal, but my girlfriends voice sounded like she was doing a mock manly voice. It sounded forcedly deep, and seemed to have an echoing quality. My own voice was like glue dribbling out of my throat. It was viscous, and sticky and sloppy. I could feel the sound travel up from my lungs out my mouth, and it all just sounded gross; like I was kinda drunk and had a horrible head cold.
Now, wanting to make the most of an auditory experience I figured Nitrous was a good idea; so out came the balloons, and BOY was that a good idea. As I took the first balloon all of the music started to swell and bulge, much like visuals might swell and bulge on other psychedelics. Before it had just sounded like it was coming out of a slightly fucked up radio; now it was coming from a giant fucked up radio echoing up from the bottom of a whale's stomach. Even after the balloon faded, the magnificence of the auditory effects remained, as if they had merely needed to be activated. Sometimes things would go back to sounding relatively normal, but then, whereas on another psychedelic there can be a sudden surge of visuals as you stand up / enter a new area / take of glasses / etc, the equivalent would happen with sound. Like the same song would be playing, my girlfriend speaking the same sentence, but suddenly a pulse would be sent out from my speakers, all the sound would bubble out like a toads throat, or rise like an ocean wave, and then expand out towards me like a auditory shockwave, momentarily distorting all sounds drastically, sometimes reducing it all to tiny and insignificant white noise, sometimes going back to that belly-of-the-whale sound.
Keep in mind that this is not entirely in sync with the Nitrous. I did a total of probably 10-15 balloons throughout the trip, and each one reliably brought one of those sound bubbles (for lack of a better word), but I spaced the balloons out, and the pulses were happening far more frequently than I was doing Nitrous, so the level of interplay there is up for debate.
Overall this was a very interesting experience. It's not exactly a fun drug. But it sure is novel. Definitely worth a try if you like to sample oddities. The Nitrous was a perfect complement. If only I had been able to play with some Helium too!
I still have 150mg or so left. I'll definitely be coming back at some point and going all in with the rest of it.
I'll probably choose DXM over Nitrous though, because of the incredibly powerful more-ishness of cracking whippets— And because K and MXE don't affect sound nearly as much IME.