This study focuses on short-term acoustic correlates of voice quality. It assesses the within-speaker stability (across different speaking styles) and between-speaker variability of measurements which compare the amplitudes of various spectral events H1*-H2*, H2*-H4*, H1*-A1*, H1*-A2* and H1*-A3*. Although speakers do differ with regard to the compactness of the parameters in read and spontaneous speaking styles, the parameters H1*-H2*, H1*-A1* and H1*-A2* appear both considerably stable for one speaker in different speaking styles and efficient in between-speaker comparisons. Though not directly applicable in forensic settings, these glottal parameters outperformed vowel formants in classification using LDA.