When do thresholds appear to be approximately the same across the test frequencies in one ear?

When thresholds appear to be approximately the same across test frequencies in one ear, this typically indicates a flat hearing loss profile. A flat hearing loss means that a person's ability to hear is relatively consistent across various frequencies, suggesting that the auditory system is affected uniformly rather than exhibiting significant variances from low to high frequencies. This can often be observed in a variety of conditions, but specifically in cases of asymmetric, flat hearing loss, both ears may present with consistent threshold levels.

In contrast, conductive hearing loss might show differences in thresholds depending on frequency, typically indicating greater difficulty in hearing at specific frequencies. High-frequency hearing loss typically leads to poorer thresholds at the higher frequencies and better thresholds at the lower frequencies, resulting in a sloping profile. Middle ear infections may also lead to fluctuating thresholds due to the variable effectiveness of sound transmission, particularly depending on fluid levels or other factors affecting the middle ear. Thus, the flat configuration of thresholds across frequencies is most characteristic of asymmetric, flat hearing loss.