To describe the masking effect of a vocalized [a:] on noise bands and speech in persons with mild-to-moderate hearing impairment (HI).
The masked threshold of noise bands (250-8000 Hz), continuous discourse, and the amount of masking produced were determined. The maximal vocalization level was determined, that still allowed the subject to just follow the continuous discourse.
Twenty persons with sensory-neural HI, twelve with a high-frequency (HF) loss and eight with low-, mid-frequency or flat (LMF) loss.
The [a:] gave a significantly higher masked threshold at 70 and 80 dBA vocalization for subjects with HF loss than for normal-hearing (NH) subjects, and somewhat higher thresholds than for those with LMF loss. The amount of masking produced was significantly smaller for subjects with HI than NH.
It is important to consider masking effects of self-produced sounds in auditory rehabilitation, and in the future design of hearing aids.