It sounded unconvincing even to her ears, but she persevered.

I already knew the speech, but it still sounded unconvincing.

Her voice sounded thin and unconvincing to her own ears.

It sounded unconvincing, but it was the best introduction he could think of.

But even to his own ears, he sounded unconvincing.

His voice sounded lame and unconvincing to the ears of the listening Shadow.

It sounded so completely unconvincing when he finally put the beginning of his carefully prepared speech into actual sound.

Morrison swallowed hard and he said, "Yes, of course," but it sounded very unconvincing, even to him.

"It will not be," said Derae, her words sounding hollow and unconvincing.

Like most such long-winded arguments it sounded unconvincing, even to me.