The relationship between Random Gap Detection and Hearing in Noise Test performances

Abstract

Background: Temporal acoustic cues are particularly important for speech understanding, and past research has inferred a relationship between temporal resolution and speech recognition in noise ability. A temporal resolution disorder is thought to affect speech understanding abilities because persons would not be able to accurately encode these frequency transitions, creating speech discrimination errors even in the presence of normal pure-tone hearing. Purpose: The primary purpose was to investigate the relationship between temporal resolution as measured by the Random Gap Detection Test (RGDT) and speech recognition in noise performance as measured by the Hearing in Noise Test (HINT) in adults with normal audiometric thresholds. The second purpose was to examine the relationship between temporal resolution and spatial release from masking. Research Design: The HINT and RGDT protocols were administered under headphones according to the guidelines specified by the developers. The HINT uses an adaptive protocol to determine the signal-to-noise ratio where the participant recognizes 50% of the sentences. For HINT conditions, the target sentences were presented at 0° and the steady-state speech-shaped noise and a four-talker babble (4TB) was presented at 0°, +90°, or -90° for noise front, noise right, and noise left conditions, respectively. The RGDT is used to evaluate temporal resolution by determining the smallest time interval between two matching stimuli that can be detected by the participant. The RGDT threshold is the shortest time interval where the participant detects a gap. Tonal (0.5, 1, 2, and 4 kHz) and click stimuli random gap subtests were presented at 60 dB HL. Tonal subtests were presented in a random order to minimize presentation order effects. Study Sample: Twenty-one young, native English-speaking participants with normal pure-tone thresholds (≤25 dB HL for 500-4000 Hz) participated in this study. The average age of the participants was 20.2 years (SD = 0.66). Data Collection and Analysis: Spearman rho correlation coefficients were conducted using SPSS 22 (IBM Corp., Armonk, NY) to determine the relationships between HINT and RGDT thresholds and derived measures (spatial advantage and composite scores). Nonparametric testing was used because of the ordinal nature of RGDT data. Results: Moderate negative correlations (p < 0.05) were found between eight RGDT and HINT threshold measures and a moderate positive correlation (p < 0.05) was found between RGDT click thresholds and HINT 4TB spatial advantage. This suggests that as temporal resolution abilities worsened, speech recognition in noise performance improved. These correlations were not statistically significant after the p value reflected the Bonferroni correction for multiple comparisons. Conclusion: The results of the present study imply that the RGDT and HINT use different temporal processes. Performance on the RGDT cannot be predicted from HINT thresholds or vice versa.