title: Influences of noise-interruption and information-bearing acoustic changes on understanding simulated electric-acoustic speech.
abstract: In simulations of electrical-acoustic stimulation (EAS), vocoded speech intelligibility is aided by preservation of low-frequency acoustic cues. However, the speech signal is often interrupted in everyday listening conditions, and effects of interruption on hybrid speech intelligibility are poorly understood. Additionally, listeners rely on information-bearing acoustic changes to understand full-spectrum speech (as measured by cochlea-scaled entropy [CSE]) and vocoded speech (CSECI), but how listeners utilize these informational changes to understand EAS speech is unclear. Here, normal-hearing participants heard noise-vocoded sentences with three to six spectral channels in two conditions: vocoder-only (80-8000 Hz) and simulated hybrid EAS (vocoded above 500 Hz; original acoustic signal below 500 Hz). In each sentence, four 80-ms intervals containing high-CSECIor low-CSECIacoustic changes were replaced with speech-shaped noise. As expected, performance improved with the preservation of low-frequency fine-structure cues (EAS). This improvement decreased for continuous EAS sentences as more spectral channels were added, but increased as more channels were added to noise-interrupted EAS sentences. Performance was impaired more when high-CSECIintervals were replaced by noise than when low-CSECIintervals were replaced, but this pattern did not differ across listening modes. Utilizing information-bearing acoustic changes to understand speech is predicted to generalize to cochlear implant users who receive EAS inputs.
authors.affiliation: Department of Psychological and Brain Sciences, University of Louisville, Louisville, Kentucky 40292, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Stilp
authors.affiliation: Department of Communication Sciences and Disorders, University of South Florida, PCD 1017, 4202 East Fowler Avenue, Tampa, Florida 33620, USA.
authors.forename: Gail
authors.initials: G
authors.lastname: Donaldson
authors.affiliation: Department of Communication Sciences and Disorders, University of South Florida, PCD 1017, 4202 East Fowler Avenue, Tampa, Florida 33620, USA.
authors.forename: Soohee
authors.initials: S
authors.lastname: Oh
authors.affiliation: Department of Communication Sciences and Disorders, Northeastern University, 226 Forsyth Building, 360 Huntington Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Ying-Yee
authors.initials: YY
authors.lastname: Kong
mesh_terms: D000161:Acoustic Stimulation; D003054:Cochlear Implants; D009622:Noise; D010470:Perceptual Masking; D013065:Speech Intelligibility; D013067:Speech Perception