Mapping measures of vocal reaction time, perceived task demand, and speech recognition to understand the benefits of on-demand processing in hearing aids

Authors: Brittany N Jaekel (Starkey)*; Jingjing Xu (Starkey); Ryan Schwantes (University of Minnesota); Michelle Hicks (Starkey)

1 Starkey
2 University of Minnesota

Background: Understanding speech in noise remains difficult for hearing-aid users. On-demand processing, when activated, prompts the hearing aid to classify the listening environment and apply additional specialized setting changes to gain, which may improve user outcomes in realistic, noisy scenarios.

Methods: 21 experienced hearing-aid users were fit with receiver-in-the-canal devices. Participants repeated sentences presented in diffuse restaurant noise. Two conditions were tested: listening with 1) default hearing-aid settings versus 2) on-demand processing enabled. Recorded responses were analyzed offline (vocal reaction times, or VRTs, were defined as the duration between stimuli offset and the onset of the participant’s response). After each condition, participants rated perceived listening effort.

Results: The main outcomes were VRT (considered a behavioral listening effort measurement, with faster responses indicating less cognitive resource consumption), perceived task demand, and speech understanding. Compared to default settings, on-demand processing significantly decreased (i.e., speeded up) VRTs, decreased perceived task demand, and increased speech understanding (all p’s <0.05). Mapping results to a grid (Fig. 1) revealed: with on-demand processing, 1) changes in perceived demand did not neatly map onto changes in VRT, indicating a potential disconnect between perceived effort and behavioral effort; 2) some participants improved speech understanding, but at a cost to cognitive resources (upper right quadrant); and 3) one participant showed potential task disengagement (lower left quadrant).

Conclusions: While on-demand processing may provide broad benefits for listening effort and speech understanding in hearing-aid users, these results support using a multiplicity of measures when evaluating outcomes to gain a fuller picture of each participant’s listening experience.