CDR copy--At the zoo, recorded and narrated by A. Greenhall, presents sounds of a lion, chimpanzee, rhea, rhinoceros, puma, and other wild animals from the Detroit Zoological Park. siris_arc_339963 ...

Ultrasonic sound waves have been used to levitate objects in crowded rooms to make hologram-like displays. Such acoustic levitation was previously only practical in empty spaces, but a new algorithm ...