Auditory density refers to the apparent compactness, concentration, or hardness of a sound. An attempt was made to determine directly the form of the density surface by the method of magnitude estimation with both pure tones and bands of noise (quarter‐octave). For both tones and noises, density grows as a power function of sound pressure. The values of the exponents decrease with frequency, and the two families of power functions converge toward a common point near about 150 dB SPL. The equal‐density contours turn out to be straight lines in a plot of SPL vs log frequency. The general slope of the equal‐density contours for pure tones was verified by a direct‐matching procedure.