Speech perception with F0mod, a cochlear implant pitch coding strategy

Abstract

D espite technological advances employed in signal processing strategies, one of the remaining obstacles are spectral gap details on the information transmitted. Considering its importance in speech perception, researchers have investigated mechanisms to optimize spectral details through virtual spectral channels. The clinical application of this technique resulted in a new approach to signal processing-the HiRes 120. Objective: To assess the auditory performance of cochlear implant users with the HiRes 120 strategy. Methodology: The literature review was conducted in an electronic database, with standard bibliographic search in the year 2011, using specific keywords. In order to select and evaluate the scientific studies found in the search, we setup search containing the following aspects: type of study, subjects, intervention used and evaluation of the results. Conclusion: Scientific evidence points to an improvement in hearing performance in noisy environments with the HiRes 120 strategy, but this does not occur in quiet situations. The optimization of speech perception with this strategy is closely related to the cochlear implant user's age, to the time of sensory deprivation and the acclimatization time required to use the strategy's spectral information. REVIEW ARTICLE Braz J Otorhinolaryngol. 2012;78(3):129-33. BJORL

Results using the OPAL strategy in Mandarin speaking cochlear implant recipients

“…This conjecture is supported by results of an earlier study with adult CI recipients which demonstrated that English sentence perception using eTone in moderate-levels of noise was comparable to that of ACE (Vandali & van Hoesel, 2012). Similar outcomes were observed by Francart et al (2015) for Flemish sentence perception using F0mod and ACE. However, in the present study, Mandarin sentence perception is also dependent to some extent on lexical tone recognition, and so we cannot rule out the possibility that any improvement in lexical tone perception in the SRT test may have balanced deficits in coding of segmental speech information, or did not directly translate to similar levels of improvement in the sentence tests (the latter perhaps due to the strong dependency of contextual information in sentence perception).…”

Reduction of the Harmonic Series Influences Musical Enjoyment With Cochlear Implants

“…27 Furthermore, Francart et al recently demonstrated that another fundamental frequency modulation (F0mod) processing strategy improves pitch perception, pitch ranking, and familiar melody identification without interfering with speech recognition. 28 These frequency manipulation studies suggest that reduction of higher harmonics might also be incorporated into future CI coding strategies to further improve music perception and enjoyment.…”

The effect of a coding strategy that removes temporally masked pulses on speech perception by cochlear implant users

“…For example, speech understanding by CI users can be improved by strategies that mimic adaptation, thereby enhancing slow speech modulations and the onsets and (for some strategies) offsets of sounds (Azadpour and Smith, 2016;Geurts and Wouters, 1999;Koning and Wouters, 2016). Similarly, improvements in pitch perception and, in some instances, speech intelligibility, have been obtained with strategies that enhance modulation coding such as F0Mod (Francart et al, 2015;Laneau et al, 2006) and eTone van Hoesel, 2012, 2011), or that combine amplitude and rate modulation, like the ARTmod strategy (Brochier et al, 2018). For the latter, speech signals are encoded by using both amplitude and rate modulation simultaneously to enhance the temporal envelope.…”

“…Thus, fluctuating masker types will lead to more complex spectral and temporal variations in SNR which may reduce or compromise the potential benefit of removing low-amplitude pulses. Further, the envelope contrast enhancements that occur with TIPS might, as with other strategies that enhance envelopes, lead to benefits in pitch or ITD coding (Francart et al, 2015;Laneau et al, 2006;Smith et al, 2013). Thus, the effect of TIPS on performance in those tasks should be considered for future evaluation.…”