Perception of Suprasegmental Speech Features via Bimodal Stimulation: Cochlear Implant on One Ear and Hearing Aid on the Other

Abstract

This study found a significant bimodal advantage for perception of all suprasegmental features, most probably due to the better low-frequency acoustic hearing that is provided by the HA. Outcomes suggest that in cases of residual hearing in the contralateral ear to the implanted ear, HA use should be encouraged.

The role of continuous low-frequency harmonicity cues for interrupted speech perception in bimodal hearing

“…Taken together, the findings of Spitzer et al (2009), Most et al (2011, Kong et al (2015), and the present study suggest that both harmonicity cues and the temporal envelope in the low-frequency region may contribute to bimodal benefit for speech recognition. When only glimpses of vocoder speech are available to the listener, the continuous signal in the LF ear (which arises from improved perception of the target speech at low frequencies) may contribute to speech perception (1) by transmitting additional segmental cues related to manner of articulation and/or F1 frequency that are absent or weakly represented in the vocoded signal, and (2) by facilitating speech segmentation, thereby enhancing identification of syllable and word boundaries.…”

“…Improved lexical segmentation and improved perception of prosodic cues have been demonstrated in previous studies of EAS benefit (e.g., Spitzer et al, 2009;Most et al, 2011). Spitzer et al (2009) investigated the possibility that lowfrequency fine-structure cues contribute to bimodal benefit by supporting lexical segmentation.…”

“…These findings support the role of low-frequency fine-structure cues for the perception of speech prosody. Most et al (2011) examined the effect of low-frequency hearing on three tasks of prosody perception (intonation discrimination, identification of syllable stress patterns, and identification of word emphasis) in CI users with varied amounts of low-frequency residual hearing in the contralateral ear. As a group, they reported significant bimodal benefit for all tasks.…”

Low-frequency fine-structure cues allow for the online use of lexical stress during spoken-word recognition in spectrally degraded speech

“…The present eye-tracking results showed that differentiating primary and secondary stress-initial words was significantly faster with simulated bimodal listening than with simulated CI listening. This finding is consistent with previous studies using pitch-related tasks, such as melody identification (e.g., Kong et al, 2005), lexical tone identification (e.g., Li et al, 2014), and question-statement discrimination (Most et al, 2011;Straatman et al, 2010), that showed improved performance with EAS listening compared to CI alone.…”

Natural history of contralateral residual hearing in unilateral cochlear implant users – long-term findings

“…The consistent use of HAs by the CI recipients in our study is in line with the reported finding that lowfrequency information (up to 0.3 kHz) may significantly improve speech perception scores even when by itself it might not offer any speech understanding [9]. It should however be emphasized that when bilateral/bimodal (CI/HA) hearing rehabilitation is chosen, HA function should be routinely monitored, the HA should be refitted as required [10], and the actual bimodal benefit should be periodically evaluated by bimodal task-specific testing [8,[11][12][13].…”