Sound, heat, and atom

Audio Perception in Humans

• Humans can perceive audio frequencies within the range of 20 Hz to 20 kHz.

Sound Waves in Air

• The wavelength range of sound waves in air at atmospheric pressure varies inversely with frequency.

Classification of Sound Waves

• Sound waves with frequencies above 20 kHz are known as ultrasound.
• Sound waves with frequencies below 20 Hz are known as infrasound.

Acoustics

• Acoustics is the interdisciplinary science that deals with the study of mechanical waves in gasses, liquids, and solids, including vibration, sound, ultrasound, and infrasound.

Temperature at the Particle Level

• Temperature describes the average kinetic energy of particles at the particle level.

Distinction between Sound and Wind

• At the particle level, sound is distinguished from wind by the coordinated motion of particles, whereas wind is characterized by random motion.

Particle Correlations in Ideal Gases

• In an ideal gas, there are no correlations between particles.

Behavior of Sound at the Particle Level

• Sound behavior at the particle level is characterized by coordinated oscillations of particles.

Main Distinction between Sound and Wind

• The main distinction between sound and wind behavior at the particle level is the coordinated motion of particles in sound waves versus the random motion of particles in wind.