Sound Equations Formula Sheet: Key Formulas & Explanations

Formula Sheet: Sound Equations

Equation	Description
v = f × λ	Speed of sound (v) is equal to frequency (f) multiplied by wavelength (λ).
f = 1/T	Frequency (f) is the reciprocal of the period (T).
v = λ/T	Speed of sound can also be expressed as wavelength (λ) divided by the period (T).
I = P/A	Intensity (I) is power (P) per unit area (A).
B = 10 log(I/I₀)	Sound level in decibels (B) is 10 times the logarithm of the intensity (I) compared to a reference intensity (I₀).
Δp = ρv	Change in pressure (Δp) is equal to density (ρ) multiplied by speed (v).
k = 2π/λ	Wave number (k) is equal to 2π divided by wavelength (λ).
ω = 2πf	Angular frequency (ω) is equal to 2π multiplied by frequency (f).
S = v × T	Distance (S) traveled by sound is speed (v) multiplied by time (T).
f_beats = |f1 - f2|	The frequency of beats (f_beats) is the absolute difference between two frequencies (f1 and f2).