Pronunciation GB: ˈləʊkəs, GA: ˈloʊkəs
The shape and extent of a formant transition is dependent on the frequency of the formant and the place/manner of articulation of the consonant concerned. So, for example, in the diagram below the sequence dɛ displays a more or less level F2 transition, while du has quite a sharp fall for the F2 transition. A comparison of all the F2 transitions for sequences beginning with d suggests that a frequency of around 1800Hz is the origin of all the transitions for this consonant. This is the F2 locus for alveolar consonants. The F2 locus for bilabials is low in frequency (<600Hz). As can be seen, all the F2 transitions for the top panel in the diagram are rising. For velars the F2 locus frequency is high (>3000Hz). All the F2 transitions in the bottom panel are falling.
Stylised spectrograms showing F1 and F2 transitions