1.  Infants are most responsive to other human voices.

2.  One concerns the tonality of the human voice.

3.  Suddenly I wanted to hear the sound of human voices and to feel the warmth and comfort of loved ones.

4.  We heard a human voice, screaming in pain.

5.  They are working on computer-generated speech that replicates the human voice.

6.  The cloth inside muffled the noise, but when he got close to the window he could make out a human voice.

7.  There was some clicking, and then the muffled sound of a human voice making its usual incomprehensible noises.

8.  Then she heard the distinctive sounds of a loquacious Siamese cat, and a human voice raised in exasperation.

9.  Instead of being answered instantly by a human voice, callers at busy times may just hear a recorded message.