When he spoke, his voice was still quiet, but it sounded friendly.

They had sounded friendly when I made the reservation weeks before, and it was less than an hour away.

There was no visible source for the sound, but it sounded friendly.

Then he said something else and it didn't sound friendly.

When she spoke, her voice sounded a little more friendly.

"Those guys by the front door don't sound too friendly," she said in a low voice.

She'd been instructed to smile at this point so her voice would sound very warm and friendly.

"Yes, I better go back to work," she said, sounding much more friendly.

But over the phone he sounded friendly enough, eager to meet.

The voice sounded friendly but the meaning was absolutely clear.