Acoustic reflexes to Schroeder-phase harmonic complexes in normal-hearing and hearing-impaired individuals

Kubli, Lina R.; Leek, Marjorie R.; Dreisbach, Laura E.

doi:10.1016/j.heares.2004.08.012

Cited by 6 publications

(7 citation statements)

References 23 publications

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“…Similar findings were reported in guinea pigs (Summers et al 2003). In NH humans, acoustic reflex thresholds are lower for −SCHR than for +SCHR (Kubli et al 2005), and HI listeners perceive much smaller differences in loudness between +SCHR and −SCHR compared to NH listeners (Mauermann and Hohmann 2007). These findings are consistent with a greater magnitude of internal stimulation in the normal auditory system occurring in response to the −SCHR.…”

Section: Introductionsupporting

confidence: 83%

“…One might make this argument, however, if NH listeners had access to other cues that were not available to HI listeners; therefore, NH listeners did not use a loudness cue. Second, while there is some evidence of loudness differences between the Schroeder-phase complexes in NH listeners, HI listeners experience those differences at a reduced level, if at all (Kubli et al 2005;Mauermann and Hohmann 2007). Thus, assuming the use of a loudness cue by HI listeners is somewhat problematic.…”

Section: Effects Of Roving Levelmentioning

confidence: 99%

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Discrimination of Time-Reversed Harmonic Complexes by Normal-Hearing and Hearing-Impaired Listeners

Lauer

Molis²,

Leek³

2009

JARO

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Normal-hearing (NH) listeners and hearing-impaired (HI) listeners detected and discriminated timereversed harmonic complexes constructed of equalamplitude harmonic components with fundamental frequencies (F0s) ranging from 50 to 800 Hz. Component starting phases were selected according to the positive and negative Schroeder-phase algorithms to produce within-period frequency sweeps with relatively flat temporal envelopes. Detection thresholds were not affected by component starting phases for either group of listeners. At presentation levels of 80 dB SPL, NH listeners could discriminate the two waveforms nearly perfectly when the F0s were less than 300-400 Hz but fell to chance performance for higher F0s. HI listeners performed significantly poorer, with reduced discrimination at several of the F0s. In contrast, at a lower presentation level meant to nearly equate sensation levels for the two groups, NH listeners' discrimination was poorer than HI listeners at most F0s. Roving presentation levels had little effect on performance by NH listeners but reduced performance by HI listeners. The differential impact of roving level suggests a weaker perception of timbre differences and a greater susceptibility to the detrimental effects of experimental uncertainty in HI listeners.

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Section: Introductionsupporting

confidence: 83%

Section: Effects Of Roving Levelmentioning

confidence: 99%

Discrimination of Time-Reversed Harmonic Complexes by Normal-Hearing and Hearing-Impaired Listeners

Lauer

Molis²,

Leek³

2009

JARO

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“…The investigation Kubli et al (2005) suggests an explanation of our data in terms of a feedback-based mechanism with a long time constant that would produce stronger effects of MPC by increasing the amount of masking by stimuli that produce greater excitation on the BM. It is unlikely that the MEMR can account for our results, since it is activated only by high-level stimuli and affects primarily low frequencies (Møller 2000).…”

Section: Possible Explanations and Mechanismsmentioning

confidence: 64%

“…Any candidate mechanism would need to produce MPC effects with an off-frequency masker and would need to have a relatively slow time course to account for the effects of masker duration. Kubli et al (2005) examined the effects of Schroeder-phase complexes with negative and positive phase curvature on the middle-ear muscle reflex (MEMR). The hypothesis they tested was that a Schroeder-phase complex with negative phase curvature should produce a more synchronized response across the BM (e.g., Dau et al 2000), is perceived as being louder (Carlyon and Datta 1997a;Mauermann and Hohmann 2007), and may thus be a more potent elicitor of the MEMR than a Schroeder-phase complex with positive phase curvature, which should produce a less synchronized response.…”

Section: Possible Explanations and Mechanismsmentioning

confidence: 99%

On- and Off-Frequency Forward Masking by Schroeder-Phase Complexes

Wojtczak

Oxenham

2009

JARO

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Forward masking by harmonic tone complexes was measured for on-and off-frequency maskers as a function of masker phase curvature for two masker durations (30 and 200 ms). For the lowest signal frequency (1 kHz), the results matched predictions based on the expected interactions between the phase curvature and amplitude compression of peripheral auditory filtering. For the higher signal frequencies (2 and 6 kHz), the data increasingly departed from predictions in two respects. First, the effects of the masker phase curvature became stronger with increasing masker duration, inconsistent with the expected effects of the fast-acting compression and time-invariant phase response of basilar membrane filtering. Second, significant effects of masker phase curvature were observed for the off-frequency masker using a 6-kHz signal, inconsistent with predictions based on linear processing of stimuli well below the signal frequency. New predictions were generated assuming an additional effect with a longer time constant, consistent with the influence of medial olivocochlear efferent activation on otoacoustic emissions in humans. Reasonable agreement between the predicted and the measured effects suggests that efferent activation is a potential candidate mechanism to explain certain spectro-temporal masking effects in human hearing.

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“…Schroeder-phase stimuli have been used to measure sensitivity to TFS with minimal envelope cues in humans and birds (Dooling et al 2002), as maskers to explore various phenomena in normal and hearingimpaired listeners (Kohlrausch and Sander 1995;Summers and Leek 1998;Summers 2000), and as a stimulus to explore the effect of phase on basilar membrane motion and the acoustic reflex (Summers et al 2003;Kubli et al 2005). Schroeder-phase harmonic complexes also appear promising for testing acoustic TFS delivery in CI users.…”

Section: Introductionmentioning

confidence: 99%

Discrimination of Schroeder-Phase Harmonic Complexes by Normal-Hearing and Cochlear-Implant Listeners

Drennan

Longnion

Ruffin

et al. 2007

JARO

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The temporal fine structure (TFS) of sound contributes significantly to the perception of music and speech in noise. The evaluation of new strategies to improve TFS delivery in cochlear implants (CIs) relies upon the assessment of fine structure encoding. Most modern CI sound processing schemes do not encode withinchannel TFS per se, but some TFS information is delivered through temporal envelope cues across multiple channels. Positive and negative Schroeder-phase harmonic complexes differ primarily in acoustic TFS and provide a potential test of TFS discrimination ability in CI users for current and future processing strategies. The ability to discriminate Schroeder-phase stimuli was evaluated in 24 CI users and 7 normal-hearing listeners at four fundamental frequencies: 50, 100, 200, and 400 Hz. The dependent variables were percent correct at each fundamental frequency, average score across all fundamental frequencies, and a maximum-likelihoodpredicted threshold fundamental frequency for 75% correct. CI listeners scored better than chance for all fundamental frequencies tested. The 50-Hz, average, and predicted threshold scores correlated significantly with consonant-nucleus-consonant word scores. The 200-Hz score correlated with a measure of speech perception in speech-shaped noise. Pitch-direction sensitivity is predicted jointly by the 400-Hz Schroeder score and a spectral ripple discrimination task. The results demonstrate that the Schroeder test is a potentially useful measure of clinically relevant temporal processing abilities in CI users.

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Acoustic reflexes to Schroeder-phase harmonic complexes in normal-hearing and hearing-impaired individuals

Cited by 6 publications

References 23 publications

Discrimination of Time-Reversed Harmonic Complexes by Normal-Hearing and Hearing-Impaired Listeners

Discrimination of Time-Reversed Harmonic Complexes by Normal-Hearing and Hearing-Impaired Listeners

On- and Off-Frequency Forward Masking by Schroeder-Phase Complexes

Discrimination of Schroeder-Phase Harmonic Complexes by Normal-Hearing and Cochlear-Implant Listeners

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