Appropriate Listening Environment and Speaking Style for Individuals with Listening Difficulties Compared with Those with Normal Hearing and Hearing Loss

Background/Objectives: Individuals with listening difficulties (LiD) report problems understanding speech despite normal hearing sensitivity. This study investigated how speech characteristics (clarity, speaking rate, and loudness) influence subjective speech understanding in adults with LiD under quiet and noisy conditions, compared with individuals with normal hearing (NH) and those who are hard of hearing (HH). Methods: A questionnaire-based survey assessed perceived speech intelligibility across 12 listening conditions created by combining two environments (quiet and noisy) and six speaking styles. Participants included 77 adults with LiD (50 LiD without developmental disorders [DD] and 27 LiD and DD), 30 adults with NH, and 26 individuals with HH. Ratings were analyzed using analysis of variance and correlation analyses. Results: Both the LiD and HH groups demonstrated significantly reduced speech understanding in noisy environments when the speaking style was suboptimal, compared with the NH group. In contrast, the LiD group uniquely reported difficulties even under quiet conditions with clear, slow, and loud speech. Loud speech in quiet conditions was not consistently beneficial, particularly in the LiD and DD group, possibly reflecting auditory hypersensitivity. Conclusions: Listening difficulties in the LiD group are influenced by environmental and speaker-related factors and cannot be addressed solely by conventional strategies used for hearing loss. Although individualized communication approaches may be required, further investigation, including experimental studies, is necessary to validate this interpretation.