To understand the mechanisms of speech perception in everyday listening environments, it is important to elucidate the relative contributions of different acoustics cues in transmitting phonetic content. Previous studies suggest that the energy envelopes of speech convey most speech content, while the temporal fine structure (TFS) can aid in segregating target speech from background noise. Despite the vast literature on TFS and speech intelligibility, the role of TFS in conveying additional speech content over what envelopes convey in complex acoustic scenes is poorly understood. The present study addresses this question using online psychophysical experiments to measure consonant identification in multi-talker babble for intelligibility-matched intact and 64-channel envelope-vocoded stimuli. Consonant confusion patterns revealed that listeners had a greater tendency in the vocoded (versus intact) condition to be biased towards reporting that they heard an unvoiced consonant, despite envelope and place cues being largely preserved. This result was replicated when babble instances were varied across independent experiments, suggesting that TFS conveys important voicing cues over what envelopes convey in multi-talker babble, a masker that is ubiquitous in everyday environments. This finding has implications for assistive listening devices that do not currently provide TFS cues, such as cochlear implants.
Comparison of temporal fine structure sensitivity and concurrent vowel perception between children with and without reading disability
