The narrator thought so.
The voice of the girl who was travelling with the narrator in the same compartment is referred to here. The blind narrator on his journey met a girl whom he started liking from the very beginning. Since the short train journey did not give him enough time to draw a mental image of the girl, he simply used his ears. The narrator considered the voice of the girl to be special as her voice reminded him of The Sparkle of a mountain stream. He gives so font of her voice that he was ready to sit with her for any length of time just to listen to her talking