Lee's Summit, MO Noise from Specific Sources: Low-Frequency Bass Limits (2026)

Section 17-252 defines pure tone technically, as any sound distinctly heard as a single pitch or a set of single pitches, and sets a one-third octave band test to identify it: a tone exists when the sound pressure level in the band containing it exceeds the average of the two adjacent bands by 5 dB for center frequencies at or above 500 Hz, by 8 dB for center frequencies between 160 and 400 Hz, and by 15 dB, the most sensitive trigger in the code, for center frequencies at or below 125 Hz, the low-frequency, bass range where bass amplifiers, subwoofers and heavy mechanical hums typically read.

Once a source is identified as a pure tone or an impulsive sound, Sec. 17-256(B) applies an across-the-board penalty: the ordinary receiving-land-use limit set in Sec. 17-256(A), 55 dba by day and 50 dba at night on residential property, 65 dba on commercial property and 70 dba on industrial property, is reduced by five (5) dba. In practice, a bass-heavy stereo or subwoofer bleeding into a residential lot at night is measured against a 45 dba ceiling instead of the normal 50 dba, because the low-frequency tonal test in Sec.

17-252 makes it far easier for booming bass to trip the 15 dB threshold than for a broadband sound like traffic to do the same. The 5 dba reduction stacks with, rather than replaces, the underlying property-boundary noise-disturbance ban in Sec. 17-254.