Any sound above 20 000 Hz is called ultrasound. It is too high pitched for humans to hear, but other animals (such as dogs, cats, dolphins and bats) can hear ultrasound. Ultrasound waves are ...

It describes how sound waves are created through vibrations, how they can be visualized using electrical devices, and how different frequencies affect pitch. The film demonstrates the properties ...

The frequency of these vibrations is what determines pitch. Low frequencies correspond ... called diffraction – the tendency of sound waves to spread out as they travel. This effect is ...

So sound waves move slower through it, which amplifies the lower frequencies in your voice. But here's the fascinating thing. The pitch of your voice hasn't changed when you inhale either gas ...

This experiment demonstrates how water affects sound waves and pitch. You'll discover how different water levels create different musical notes and learn about the relationship between mass, vibration ...