I can see the features listed as being useful in separate scenarios, but is it essential that all three features be incorporated at once?
ie: that the room itself be fully soundproof, that the microphone and space be studio quality (as in the case of voiceover audition recordings), and that the room be transparent? Are you reliant on a solution that allows versatility for multiple situations?
In the scenarios I can imagine, aside from it being nice to have, it seems the user would not strongly require all three at once in any of them at a given time.
These scenarios would be:
A. Record sound at studio quality wherever you are.
B. Make calls in a transparent but sound-reducing room such as a transparent “office” in an otherwise open-plan area.
C. Want to concentrate alone without being distracted by people/noises outside (such as while reading or studying or solo working - no need for recording here).
In the case of A, you have a very specific set of needs and would be building your structure with those in mind. To me, it seems unlikely there would be use cases where you want the level of sound quality of an album recording or a movie set where you also would want to engage with the outside world.
Here is a sound-blocking material that is transparent and also flexible - Vinyl Strip Curtains (as hard surfaces reverberate the sound back) but have only seen it recommended for preventing noise bleed in really loud industrial environments (eg factories) no mention of it for actual recording studios - for that quality you might need actual acoustic blankets.
In the cases where you would want professional studio recording quality, I would suggest scrapping the transparent walls requirement as it would massively constrain what you can do in terms of achieving studio-quality soundproofing, and you wouldn’t be utilising the transparency feature in such cases.
In terms of B, The goals here would be to:
have your own designated area
see/interact with outside if needed
make calls without background noise by default
In this case, using the abovementioned Vinyl Strip curtains would make sense although they might be overkill (and heavy to lug around).
Sound recording and Soundproofing:
Recording studio-quality microphones are massively expensive if you don’t need them.
In order to utilise them you’d need proper soundproofing, otherwise, they will pick up all the ambient noise.
Soundproofing is an ambiguous term that does not necessarily refer to noise blocking, there are three things one can generally be referring to in that term: blocking the sound from outside, blocking sound from inside or using sound absorption.
All three would need to be very precisely balanced in creating a portable recording studio scenario A and if we are dropping the transparency requirement there are many options.
This video shows different levels of soundproofing with different numbers of acoustic blankets
Alternatively, you could either buy something like this which fits in a duffel bag, the benefit of this is that it has been predesigned and equalised, which is one of the main difficulties when setting up a sound booth, although for people who don’t mind doing that it's also apparently pretty easy to build your own sound recording booth with PVC pipes and the right kind of heavy blankets.
There are many articles like this one (which even has blueprints) on how to DIY a small soundproof PVC booth for easy assemble/disassemble.
Communications-level clarity/noise-prevention/ noise-cancellation
For the call-box scenario B, high quality for general communications can be achieved without requiring studio equipment, which is very expensive and requires proper setup in order to equalize. Even if you did opt for professional equipment and a full sound studio setup, you would almost certainly lose that quality in the VOIP call itself as many communication platforms use "lossy" compression (compression that loses the original quality) to better handle multiple connections, so investing in that equipment if this is your use case would have no benefit here.
Very often you are better off with a less sensitive microphone (to avoid picking up ambient room noise) closer to your mouth, such as a headset mic which is a far cheaper and easier way to have clear communication. Whether on a headset or not, the important thing is that it be a dedicated microphone, not an inbuilt one (which are generally almost as terrible quality as laptop microphones). It is actually really easy to get hold of low-priced microphones that are still great quality for making calls if you find a reliable brand and a well-reviewed model.
Without the requirement for studio quality, you would likely not need your walls to be heavily sound-reducing, as a voice favouring microphone and noise-cancelling headphones/headset would more than accommodate your needs, however, there are solutions like the aforementioned vinyl strip curtains to help with one-way or two-way noise reduction in scenario B and C if you do favour extreme silence or are really averse to headsets.