Recent studies have shown that the acoustic relationship between the murmur and the vowel at the nasal-vowel boundary is highly informative for the [m]-[n] distinction. In the present paper, the contribution of relational information is reassessed by classifying 1946 syllable-initial and 2848 syllable-final nasal consonants taken from continuous speech data. Relational information in the acoustic waveform is based on difference spectra, in which spectral information in the vowel is subtracted from spectral information in the murmur, and on combined spectra in which classifications are made from combinations of murmur and vowel spectra. These two kinds of relational spectra are compared with static spectra, in which single spectral slices are taken in either the murmur or the vowel. Contrary to recent theoretical predictions, difference spectra are shown to perform more poorly than some kinds of static spectra. However, since classification scores from combined spectra are better than from either static or difference spectra, cues to nasal place of articulation can nevertheless be defined as relational. In the best scoring combined spectra, classification scores on open tests are just under 94% correct for syllable-initial nasals and just under 82% correct for syllable-final nasals. The high classification scores show that there is considerable information in the acoustic waveform for identifying nasal place of articulation from continuous speech data.