voice in the wilderness

idiomatic rare

(idiomatic) A person, publication, or other source of assertions that expresses an opinion, doctrine, or point of view which is ignored or rejected by almost all others; the actual utterance of an unpopular opinion, doctrine, or point of view.

Japanese Meaning

ほとんどの人に無視されたり拒絶されたりする意見や主義を主張する人、出版物、またはその他の情報源としての存在 / 孤立した立場から、あまり支持されない意見や考えを表明する行為またはそれをなす存在

What is this buttons?

Despite repeated warnings about the riverbank's erosion, his reports were treated as a voice in the wilderness.

Google Translation / DeepL Translation

度重なる河岸侵食の警告にもかかわらず、彼の報告は誰にも相手にされない孤立した声のように扱われた。

Details

Sense（1）

Eysenck (1952) was just beginning to seriously question the validity of dynamically oriented therapy, but he was a lone voice in the wilderness at that time. Not until the sixties did opposing points of view . . . begin to gain prominence.

Google Translation / DeepL Translation