Ambiguity of Carhart''s notch (comments to the article: Ivanov A.I. et al. "Experimental study of the relationship of speech characteristics and the state of the hearing in pilots with sensorineural hearing loss")
The adequacy of noise-induced hearing loss (NIHL) assessment at 4000 Hz («Carhart's notch») is considered as applied to identify its connection with possible speech disorders. The failure of the authors isexplained by the non-linearity of the NIHL value in this frequency range and it is proposed to use frequencies from the band of «social hearing», e.g. 1000 Hz. The importance of the studies is noted and their continuationis recommended.