When Konan gave a lecture, his voice was extremely beautiful and Shigeki KAIZUKA, Konan's student, stated in retrospect that he thought Konan's voice was the very 'Kinseigyokushin' (an extremely veautiful voice).
講義するときの声が極めて美しく、「金声玉振」とはこのことかと弟子の貝塚茂樹が回想している。