ABLB laddergram rung divergence reveals whether loudness grows faster in an impaired ear

Evidence

In one approach, the patient hears the reference tone in this good ear and tells the audiologist to increase or decrease the level of the sound in his impaired ear until it is equally loud to the tone in his healthy ear. Another approach is to present the fixed tone to the impaired ear. Whatever the approach, the audiologist repeats the measurement at another level (usually in 10 or 20 dB steps, depending on the degree of hearing loss). The audiologist then plots a laddergram, in which one rung of the ladder plots the dB HL levels in the healthy ear and the other rung of the ladder shows the loudness-matched levels (in dB HL) in the impaired ear. Figure 8–1 illustrates that a laddergram from a patient with recruitment in the right ear will show non-parallel rungs (loudness will grow faster in the impaired ear than in the healthy one; see the right panel of Figure 8–1). An ear that does not exhibit recruitment will show parallel rungs (see the left panel of Figure 8–1). This type of laddergram might be indicative of retrocochlear pathology. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1753

Categorization

• DEFINE: Describes the laddergram tool used to visualize recruitment and its absence.