Using consonant confusion to predict unexplained hearing loss

Abstract

Some listeners have difficulty understanding speech in noise that is not explained by traditional audiometry. Speech perception errors can manifest as consonant confusions such as /s/ for /sh/. Consonant confusions contain information that may be used to detect or quantify unexplained hearing loss. We developed an efficient consonant confusion test, Quick-VC, based on ten vowel-consonant-vowel (VCV) phonemes. Speech spectrum noise was added to each VCV to make consonant confusions sensitive to hearing impairment. Puretone threshold averages and consonant confusion matrices were collected from 15 listeners with normal hearing and 45 listeners with hearing loss. A logistic regression with regularized coefficients was performed on principal components of the consonant confusions. After removing the effect of audibility, the model predicted unexplained hearing loss greater than 5 dB for seven individuals with a cross-validated area under the curve (AUC) of 0.757, which is clinically acceptable. Six of these seven listeners reported bilateral tinnitus and four had a history of noise exposure, which implicates the peripheral auditory system. The Quick-VC test may be a valuable tool for identifying and quantifying unexplained hearing difficulties, perhaps due to partial loss of auditory nerve fibers, for which there is currently no clinical test.