Physics » Sound and the Physics of Hearing » Sound Interference and Resonance: Standing Waves in Air Columns

# Summarizing Sound Interference and Resonance

## Summary

• Sound interference and resonance have the same properties as defined for all waves.
• In air columns, the lowest-frequency resonance is called the fundamental, whereas all higher resonant frequencies are called overtones. Collectively, they are called harmonics.
• The resonant frequencies of a tube closed at one end are:

$${f}_{n}=n\cfrac{{v}_{w}}{4L}\text{,}n=1, 3, 5\text{.}\text{.}\text{.,}$$

$${f}_{1}$$ is the fundamental and $$L$$ is the length of the tube.

• The resonant frequencies of a tube open at both ends are:

$${f}_{n}=n\cfrac{{v}_{w}}{2L}\text{,}n=1, 2, 3\text{.}\text{.}\text{.}$$

## Glossary

### antinode

point of maximum displacement

### node

point of zero displacement

### fundamental

the lowest-frequency resonance

### overtones

all resonant frequencies higher than the fundamental

### harmonics

the term used to refer collectively to the fundamental and its overtones