Table 1

Parameters for clinical description of the hearing impairment

(1) Hearing impairment in dB HL (averaged on 0.5-1-2 kHz)
Moderate40–69 dB HL
Severe70–94 dB HL
Profound>95 dB HL
(2) Age of onset
CongenitalPresent at birth
UncertainWhen it was difficult to ascertain the real congenital onset
(3) Symmetrical/asymmetrical involvement
Asymmetrical>15 dB difference between ears in at least two frequencies
(4) Steady/progressive deficit
Progressive>15 dB of progressiveness in at least two frequencies or >10 dB for average of 4 frequencies (0.5-4 kHz)
(5) Configuration of audiogram
Low frequencies>15 dB from the better to the poorer hearing threshold at the low frequencies to the mid frequencies
Sloping>15 dB difference between 1000 and 4000 Hz
Flat<15 dB difference from 500 to 4000 Hz
U shapedWith >15 dB difference between the better hearing thresholds and the poorer hearing threshold(s)
None of the above configurations