Prediction of conductive hearing loss using wideband acoustic immittance

The purpose of this article was to review the effectiveness of wideband acoustic immittance (WAI) and tympanometry in detecting conductive hearing loss (CHL). Eight studies were included that measured CHL through air-and bone-conducted thresholds in at least a portion of their participants. One study included infants, three studies included children, one study included older children and adults, and three studies included adults. WAI identified CHL well in all populations. In infants and children, WAI in several single-frequency bands identified CHL with equal accuracy to measures of middle ear admittance using clinical tympanometry with a single probe tone (1000 Hz for infants; 226 Hz for children and adults). When WAI was combined across frequency bands, it identified CHL superior to traditional, single-frequency tympanometry. Only two studies used WAI tympanometry, which assesses the outer/middle ear across both frequency and introduced air pressure, and differing results were reported as to whether introducing pressure into the ear canal provides better identification of CHL. In general, WAI appears to be a promising clinical tool, and further investigation is warranted.