The tones of Tamang (Sino-Tibetan family) involve both F0 and voice quality characteristics: two of the four tones (tones 3 and 4) were reported to be breathy in studies from the 1970s. For the present research (thirty years later), audio and electroglottographic data were collected from 5 speakers of the Risiangku dialect in their 30s or 40s. Voice quality is estimated by computing the glottal open quotient. The present results bear on 788 syllables (from a corpus of 6,500). They show that in the speech of three speakers (M2, M3, M5), tones 3 and 4 have a higher open quotient (which provides an indirect cue to the degree of breathiness) than tones 1 and 2, with tone 3 more clearly so than tone 4, especially for speaker M2. The difference in open quotient between the four tones for the other two speakers is negligible or inconsistent. The Tamang data are compared with similar data from Naxi, which possesses level tones, and from Vietnamese, which possesses pitch-plus-voice-quality tones. The comparison brings out the great variability of Tamang tones in terms of F0, as well as in terms of open quotient. The present results appear to confirm that Tamang tones possess several correlates; they offer an insight on ongoing change in the prosodic system of Tamang.