Psychophysical studies for two multiple-channel cochlear implant patients

Tong, Y. C.; Clark, Graeme M.; Blamey, Peter J.; Busby, P. A.; Dowell, Richard C.

doi:10.1121/1.387342

Cited by 110 publications

(68 citation statements)

References 13 publications

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“…A number of authors have suggested that psychophysical stimuli can be used to understand individual differences between CI users (Tong et al 1982, Shannon 1983 as well as to probe the detailed effects of CI signal processing (Henry et al 2000). The results from the present study are relevant for CI signal processing developments that attempt to improve CI pitch perception.…”

Section: Discussionmentioning

confidence: 99%

“…Studies (Pretorius andHanekom 2008, Goldsworthy et al 2013) have found CI discrimination thresholds between 5 and 30 %; furthermore, Vandali et al (2014) demonstrated that training can improve CI discrimination thresholds by more than a factor of 2. While the use of synthetic tones presented through the CI processor is relatively unexplored, there is a rich literature investigating CI pitch perception based on electrode psychophysics (Tong et al 1982;McDermott and McKay 1997;Hanekom and Shannon 1998;Zeng 2002;Henry and Turner 2003;Carlyon et al 2010;Hughes and Goulson 2011;Goldsworthy and Shannon 2014) as well as using more natural stimuli (Fujita and Ito 1999;Gfeller et al 2002;McDermott 2004;Looi et al 2008). In the present article, the suggestion put forth by Pretorius and Hanekom (2008) that pure and complex tones can be used to probe different aspects of perception is extended toward understanding correlations with phoneme identification in noise.…”

Section: Introductionmentioning

confidence: 99%

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Correlations Between Pitch and Phoneme Perception in Cochlear Implant Users and Their Normal Hearing Peers

Goldsworthy

2015

JARO

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This study examined correlations between pitch and phoneme perception for nine cochlear implant users and nine normal hearing listeners. Pure tone frequency discrimination thresholds were measured for frequencies of 500, 1000, and 2000 Hz. Complex tone fundamental frequency (F0) discrimination thresholds were measured for F0s of 110, 220, and 440 Hz. The effects of amplitude and frequency roving were measured under the rationale that individuals who are robust to such perturbations would perform better on phoneme perception measures. Phoneme identification was measured using consonant and vowel materials in quiet, in stationary speech-shaped noise (SSN), in spectrally notched SSN, and in temporally gated SSN. Cochlear implant pure tone frequency discrimination thresholds ranged between 1.5 and 9.9 %, while cochlear implant complex tone F0 discrimination thresholds ranged between 2.6 and 28.5 %. On average, cochlear implant users had 5.3 dB of masking release for consonants and 8.4 dB of masking release for vowels when measured in temporally gated SSN compared to stationary SSN. Correlations with phoneme identification measures were generally higher for complex tone discrimination measures than for pure tone discrimination measures. Correlations with phoneme identification measures were also generally higher for pitch perception measures that included amplitude and frequency roving. The strongest correlations were observed for measures of complex tone F0 discrimination with phoneme identification in temporally gated SSN. The results of this study suggest that musical training or signal processing strategies that improve F0 discrimination should improve consonant identification in fluctuating noise.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Correlations Between Pitch and Phoneme Perception in Cochlear Implant Users and Their Normal Hearing Peers

Goldsworthy

2015

JARO

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“…Previous pitch-ranking studies in traditional cochlear implant users have indicated that both electrode location (place pitch cues) and stimulation rate (temporal pitch cues) can influence the perceived pitch (e.g., Tong et al 1982;Shannon 1983;Townshend et al 1987;McKay et al 2000). For instance, a more basal electrode will elicit a higher pitch than a more apical one, and a higher stimulation rate will elicit a higher pitch than a lower rate, up to around 300 Hz where the rate pitch cue saturates.…”

Section: Introductionmentioning

confidence: 99%

Changes in Pitch with a Cochlear Implant Over Time

Reiss

Turner

Erenberg

et al. 2007

JARO

140

143

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In the normal auditory system, the perceived pitch of a tone is closely linked to the cochlear place of vibration. It has generally been assumed that highrate electrical stimulation by a cochlear implant electrode also evokes a pitch sensation corresponding to the electrode_s cochlear place (Bplaceĉ ode) and stimulation rate (Btemporal^code). However, other factors may affect electric pitch sensation, such as a substantial loss of nearby nerve fibers or even higher-level perceptual changes due to experience. The goals of this study were to measure electric pitch sensations in hybrid (short-electrode) cochlear implant patients and to examine which factors might contribute to the perceived pitch. To look at effects of experience, electric pitch sensations were compared with acoustic tone references presented to the non-implanted ear at various stages of implant use, ranging from hookup to 5 years. Here, we show that electric pitch perception often shifts in frequency, sometimes by as much as two octaves, during the first few years of implant use. Additional pitch measurements in more recently implanted patients at shorter time intervals up to 1 year of implant use suggest two likely contributions to these observed pitch shifts: intersession variability (up to one octave) and slow, systematic changes over time. We also found that the early pitch sensations for a constant electrode location can vary greatly across subjects and that these variations are strongly correlated with speech reception performance. Specifically, patients with an early low-pitch sensation tend to perform poorly with the implant compared to those with an early high-pitch sensation, which may be linked to less nerve survival in the basal end of the cochlea in the low-pitch patients. In contrast, late pitch sensations show no correlation with speech perception. These results together suggest that early pitch sensations may more closely reflect peripheral innervation patterns, while later pitch sensations may reflect higher-level, experience-dependent changes. These pitch shifts over time not only raise questions for strict place-based theories of pitch perception, but also imply that experience may have a greater influence on cochlear implant perception than previously thought.

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“…Psychophysical studies have revealed that there are two basic cues for pitch perception in cochlear implant subjects (Tong et al 1982;Townshend et al 1987) and that these cues are independent of each other Tong et al 1983). The first cue is related to the site of excitation along the cochlea (place pitch).…”

Section: Introduction and Outlinementioning

confidence: 99%

Multichannel Place Pitch Sensitivity in Cochlear Implant Recipients

Laneau

Wouters

2004

JARO

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Cochlear implant recipients perceive a rise in pitch when the site of stimulation is moved from the apex toward the base. The place pitch sensitivity is typically measured using the stimulation of single channels. However, all current cochlear implant devices stimulate multiple channels simultaneously or with pulses temporally interleaved. The primary goal of the present study is to test whether the sensitivity of a cochlear implant recipient to changes in perceived pitch associated with changes of place of excitation improves or deteriorates when the number of active channels is increased, compared with stimulation with only one active channel. Place pitch sensitivity was recorded in four Nucleus CI24 subjects as a function of number of active channels (from 1 to 8). Just noticeable differences were estimated from a constant stimuli 2AFC pitch-ranking experiment with roving loudness. Reference and comparison stimuli contained the same number of active channels but were shifted one or two electrodes toward the base or toward the apex. The place pitch sensitivity was measured using monopolar stimulation at two locations along the electrode array. To minimize cues related to loudness, the multichannel stimuli were loudness balanced relative to the single-channel stimuli presented at C-level. The number of active channels did not affect place pitch sensitivity. This is consistent with a model that compares the edges of the excitation pattern irrespective of the overlap between excitation patterns. There was a significant difference in sensitivity to place pitch among subjects.The average just noticeable differences of place pitch, extrapolated from a fitting procedure, for the subjects ranged from 0.25 mm to 0.46 mm.

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Psychophysical studies for two multiple-channel cochlear implant patients

Cited by 110 publications

References 13 publications

Correlations Between Pitch and Phoneme Perception in Cochlear Implant Users and Their Normal Hearing Peers

Correlations Between Pitch and Phoneme Perception in Cochlear Implant Users and Their Normal Hearing Peers

Changes in Pitch with a Cochlear Implant Over Time

Multichannel Place Pitch Sensitivity in Cochlear Implant Recipients

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