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Date of Graduation
Doctor of Audiology (AuD)
Department of Communication Sciences and Disorders
This study examined the effect of a new speech processing strategy (SpeechZone2) in a commercially available hearing aid on speech understanding in noise and self-reported listening effort. Seven adult, experienced hearing aid users (2 males, 5 females; mean age = 64.6 years) with mild to severe, sloping sensorineural hearing loss participated in this study. Binaural Unitron Flex receiver in the ear style hearing aids with closed domes were used to provide the manufacturer prescribed amplification for each participant. The hearing aids were programmed with two separate memories: 1) omnidirectional microphone without SpeecZone2 processing, and 2) adaptive directionality with SpeechZone2 processing. The participants were seated in the center of a five loudspeaker fixed array. HINT scores (dB SNR required for 50% speech understanding) with the speech source at 00, 900, 1800, and 2700 azimuths were measured for each program while uncorrelated speech babble noise was presented simultaneously from four speakers. The participants were also asked to fill out a short questionnaire on listening effort after each condition. Results showed that the new speech processing algorithm (adaptive directionality with SpeechZone2) did not improve speech understanding in noise compared to the omnidirectional microphone condition (F(1,6)= 1.723; p = 0.237). Pairwise comparison with Bonferroni corrections (α=0.0125) indicated that there was a significant improvement only when speech was presented from 270 degree azimuth (p=0.002). The ANOVA also revealed a significant effect of the speech source location (F(3,18)= 5.62; p=0.02). Regardless of the directionality and speech processing, the participants performed better when speech was presented from the sides (900 and 2700). A Wilcoxon signed-rank nonparametric test showed that there was no significant difference in the self-reported scores in the listening effort questionnaire (Z = 0.637, p = 0.39). There was a large intersubject variability noticed in this small sample size.
Compton, Abigail E., "Speech understanding and listening effort in noise with a new speech processing algorithm" (2020). Dissertations, 2020-current. 18.