Low frequency noise, which can arise from a variety of environmental sources, frequently gives rise to complaints of noise annoyance, which are not necessarily predicted on the basis of conventional dB(A) assessment. This paper, which is particularly concerned with the noise arising from music with a heavy 'beat', considers the extent to which dB(A) underestimates low frequency noise and proposes a rating procedure based on the use of dB(A) and dB(C) measurements.