My ballot for 「絶対語感{ぜったいごかん}」. It's not a translation of "Sprachgefühl" but a variation on the Japanese word 「絶対音感{ぜったいおんかん} (absolute pitch) 」, which names the ability to intuitively recognize and reproduce a given musical note.
So 「絶対語感」 and "Sprachgefühl" may not line up directly, but, I think they are pretty much doppelgängers of each other, at least in terms of meaning. Plus the word 「絶対語感」has a neat look, ring and feel (its 語感, if you will) and that never-heard-of-it-but-can-guess-what-it-means quality to it (for speakers of Japanese, anyway), which may be just as well in this case.
But what does 「絶対語感」 mean, exactly? The ability to intuit whether a given word or string of words are grammatically or idiomatically felicitous?
While I think it's synonymous with the dictionary definition of "Sprachgefühl", it's not a widely-used term, and its definition is nowhere near as well-established as that of 「絶対音感」 or presumably of "Sprachgefühl". And unlike the pitch of sound, grammar and usage and idiom and pronunciation are not strictly language-wide, universally agreed-upon phenomena. They may vary from region to region, from generation to generation, even from one person to another.
It seems 「絶対語感」 owes what currency it has at the moment to the linguist Shigehiko Toyama, who boasts a rather impressive oeuvre, among which is "わが子に伝える「絶対語感」 頭の良い子に育てる日本語の話し方".
Unfortunately I don't have any of his books, but as luck would have it I've found a blog post that purports to quote him as explaining what he intends the word to mean, in one of his books "大人の言葉づかい". Here's my partial TL
of it (Expect and pardon mistranslations, though I try to keep them as few and forgivable as possible.):
What "絶対語感" is, it is the linguistic fabric of a given person. Grammar is part of it; when one hears such an utterance as 「あの人はりっぱな本に持っている」, immediately they judge it as incorrect. However, under normal circumstances, the judging person themselves does not have a clear consciousness of what their version of grammar is like, nor can they write it down on paper.
Rhythm and pitch too are encompassed within the scope of 絶対語感. When people from the Kansai region feel Tokyoites' speech to be "foreign", it is due to the difference in their 絶対語感.
The 絶対語感 of people who speak of 「食べられる」「着られる」「寝られる」 is distinct from that of those in the habit of saying 「食べれる」「着れる」「寝れる」(*TN: the much maligned 「ら抜きことば」). Though they deem the usage improper, they find it hard to say that aloud. In some dialects the 「ら抜きことば」 has long been part of correct usage.
スプラゲーフー>> Sprachgefühl をカタカナにする場合、通常は「シュプラッハゲフュール」と書かれると思います