Early audiogram standardization debates concerned level units and axes, not frequency scaling.

Evidence

At the time, it was standard to quantify frequency in cycles per second (note: the unit hertz was not established until 1930), and at the time, Wegel had already been plotting frequency in octaves, rather than using a linear scale. However, there was no standard for depicting the level (y) axis, and this was a topic hot for discussion. Two issues were of interest: the units to be used and the scale on which the thresholds should be plotted. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 92

Categorization

• XREF: Wegel plotting frequency in octaves anticipates the modern audiogram’s log-frequency axis; connects to why audiograms today look the way they do.