Objectives: A considerable portion of hearing-impaired patients show disproportional loss in speech intelligibility with respect to their pure tone audiogram. This study investigated the relationship between tone decay (TD) and unaided or aided word recognition scores (WRS).
Design: A prospective observational study.
Study sample: Fifty-one participants with sensorineural hearing loss of less than 80 dB HL or a maximum WRS of at least 5% were included. All participants were using hearing aids.
Results: Two-thirds of the participants exhibited a TD of at least 10 dB. In this subpopulation, the additional loss of audibility caused by TD reached up to 21 dB in the main speech frequency range. The maximum TD - assessed between 0.5 and 4 kHz - explained up to 18% of the variability in aided WRSs.
Conclusions: In cases of disproportionately high loss of speech intelligibility, the TD test (TDT) provides a tangible audiological marker that complements pure-tone audiometry and WRS measurements. It may influence therapeutic decision-making in the management of hearing loss, as TD limits WRS. The additional assessment of TD has the potential to enhance our understanding of the diverse aetiologies underlying hearing impairment, thereby supporting the development of more targeted diagnostic and therapeutic strategies.