Nonlinguistic Outcome Measures in Adult Cochlear Implant Users Over the First Year of Implantation

Abstract

Objectives Post-lingually deaf cochlear implant users’ speech perception improves over several months after implantation due to a learning process which involves integration of the new acoustic information presented by the device. Basic tests of hearing acuity might evaluate sensitivity to the new acoustic information and be less sensitive to learning effects. It was hypothesized that, unlike speech perception, basic spectral and temporal discrimination abilities will not change over the first year of implant use. If there were limited change over time and the test scores were correlated with clinical outcome, the tests might be useful for acute diagnostic assessments of hearing ability and also useful for testing speakers of any language, many of which do not have validated speech tests. Design Ten newly implanted cochlear implant users were tested for speech understanding in quiet and in noise at 1 and 12 months post activation. Spectral-ripple discrimination, temporal-modulation detection, and Schroeder-phase discrimination abilities were evaluated at 1, 3, 6, 9 and 12 months post activation. Results Speech understanding in quiet improved between 1 and 12 months post activation (mean 8% improvement). Speech in noise performance showed no statistically significant improvement. Mean spectral-ripple discrimination thresholds and temporal-modulation detection thresholds for modulation frequencies of 100 Hz and above also showed no significant improvement. Spectral-ripple discrimination thresholds were significantly correlated with speech understanding. Low frequency modulation detection and Schroeder-phase discrimination abilities improved over the period. Individual learning trends varied, but the majority of listeners followed the same stable pattern as group data. Conclusions Spectral-ripple discrimination ability and temporal-modulation detection at 100-Hz modulation and above might serve as a useful diagnostic tool for early acute assessment of cochlear implant outcome for listeners speaking any native language.

Effects of age and hearing mechanism on spectral resolution in normal hearing and cochlear-implanted listeners

“…Measures of spectral resolution have been shown to strongly correlate with open-set speech understanding in both post-lingually deaf adult CI users (Henry and Turner, 2003;Henry et al, 2005;Won et al, 2007;Saoji et al, 2009;Green et al, 2014;Winn and Litovsky, 2015) as well as in pre-lingually deaf school-age children with CIs (Jung et al, 2012). Although various approaches have their merits, SRD is an efficient method to test spectral resolution that does not require any knowledge of phonemic or linguistic structure (Drennan et al, , 2016. In SRD, listeners discriminate between two spectrallymodulated noise stimuli with shifted spectral envelope phases (Supin et al, 1994a(Supin et al, , 1994b(Supin et al, , 1999.…”

Spectral Ripple Discrimination in Normal-Hearing Infants

“…Although spectral ripple discrimination has recently been shown to be a promising clinical marker of auditory acuity in adult, post-lingually deaf, CI users (Drennan et al 2014, Shim et al 2014, Drennan et al 2015), little is known about how performance on this measure changes with development. Although spectral resolution might prove to be a relatively stable and acute measure of device efficacy for adults, it is important to understand how spectral resolution is affected by development before measures of spectral resolution can be applied effectively to young listeners with CIs.…”

“…Spectral resolution has shown promise as a proxy measure of speech perception to assess device candidacy and measure effectiveness of signal processing strategies (Drennan et al 2014, Shim et al 2014, Drennan et al 2015). Given that spectral resolution is robustly related to speech perception for adult CI listeners, some investigators have suggested that it could be useful for testing device efficacy in infants with CIs or HAs who are too young for clinical measures of speech perception (Won et al 2011, Drennan et al 2014).…”

Comparison of the Spectral-Temporally Modulated Ripple Test With the Arizona Biomedical Institute Sentence Test in Cochlear Implant Users

“…In general, it has been shown that better spectral resolution correlates with better speech recognition in noise for CI users (Drennan et al 2016; Henry & Turner 2003; Holden et al 2016; Won et al 2007; however, see Langner et al 2017). It has also been shown that simulating broad activation patterns in normal hearing listeners via a vocoder results in deterioration of both spectral resolution and vowel recognition (Litvak et al 2007).…”

“…It has also been shown that simulating broad activation patterns in normal hearing listeners via a vocoder results in deterioration of both spectral resolution and vowel recognition (Litvak et al 2007). Additionally, spectral resolution tests involve minimal learning (Drennan et al 2016; Won et al 2007), indicating the potential use for these tests after remapping in predicting which adjustments may result in optimal speech perception in noise.…”