Temporal Fine Structure Frequency Bands Criticality in Perception of the Speech in the Presence of Noise

Abstract

Context: In the competing background, noise speech cues are compromised. In quiet and noisy conditions, the distribution and weighting of temporal cues for the speech perception vary across different frequency spectrum. Temporal fine structure (TFS) cues help in perceiving speech in noise. Knowledge about the perceptual weighing of fine structure cues is essential for the design of assistive listening devices Aims: In the present study, the perceptual weighing of the fine structure cues across frequency bands in different listening conditions is measured. Settings and Design: Data were collected in a double room set up and adapted Plomp (1986) sentence speech recognition threshold (sSRT) method was used. Subjects and Methods: Forty normal hearing individuals presented without and with (very low frequency [VLF], low frequency, mid frequency [MF], and high frequency) filtered fine structure bands of hearing in noise test sentences. sSRTs were measured for uninterrupted and interrupted stimulus in different signal to noise conditions (quiet, 0 dB, +10 dB, and −10 dB). ANOVA, post hoc, and bivariate Karl Pearson correlation statistical analysis were used. Results: The sentence recognition for filtered stimulus in quiet and in noise resulted in significantly higher relative perceptual weight placed upon the TFS in the VLF band and MF at 0 dB signal to noise ratio (SNR) (P < 0.001). The relative weighting of fine structure cues demonstrated the importance VLF band in quiet and noisy conditions and of the MF band that contains dynamic formant movement at 0 dB SNR condition.