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Ratkute, V.

Publications and source records attributed to Ratkute, V..

3 recordsLinked to original sources

Ecological validity of masking release with speech-like stimuli

The relevance of masking release by comodulation and interaural phase difference (IPD) for speech perception is still unclear. We used speech-like stimuli to link spectro-temporal properties of formants with masking release. The stimuli comprised a tone and three masker bands centered at formant frequencies F1, F2, and F3 derived from a consonant-vowel (/gu/, /fu/, and /pu/). The target was a diotic or dichotic frequency-modulated tone following F2 trajectories. Results showed no statistically significant comodulation masking release (CMR), while the binaural masking level difference (BMLD) was comparable to previous findings. The data suggest that factors other than comodulation may play a dominant role in grouping frequency components in speech.

animal behavior and cognition↗

The effect of the preceding masking noise on monaural and binaural release from masking

Auditory stream segregation can be facilitated when the maskers share coherent amplitude modulations or by utilizing spatial cues. The effectiveness of each cue can be quantified as a decrease in masked thresholds, termed as comodulated masking release (CMR) and binaural masking level difference (BMLD). Prolonged exposure to the masker can influence following target segregation. However, the collective impact preceding noise on target segregation in the presence of comodulation and interaural phase difference (IPD) cues is unclear. Stimuli were used to induce noise streams by altering the duration and temporal coherence of the envelope of the preceding masker. The effect on following target detection with CMR and BMLD induced by an IPD of the target tone was investigated. The results indicate that the effect of the preceding stream formation on CMR operates on different time scales, extending beyond 200 ms, depending on the spectrotemporal characteristics of the maskers. However, the effect on IPD-induced BMLD was not significant across time. Under the simplifying assumption that peripheral processing operates on shorter time scales than cortical processing, the results of the present study may provide insights into auditory signal processing in the presence of beneficial cues for target stream segregation.

neuroscience↗

Neural correlates of masked and unmasked tones: psychoacoustics and late auditory evoked potentials (LAEPs)

Hearing thresholds are commonly used to quantify a listeners ability to detect sound. In the presence of masking sounds, hearing thresholds can vary depending on the signal properties of the target and the masker, commonly referred to as auditory cues. Target detection can be facilitated with comodulated masking noise and interaural phase disparity (IPD). This can be quantified with a decrease in detection thresholds or masking release: comodulation masking release (CMR, for comodulation) and binaural masking level difference (BMLD, for IPD). As these measures only reflect the low limit of levels for target detection, the relevance of masking release at supra-threshold levels is still unclear. Here, we used psychoacoustic and electrophysiological measures to investigate the effect of masking release for a masked tone at supra-threshold levels. Behaviorally, we investigated how the amount of masking release affects the salience at supra-threshold levels. We used intensity just-noticeable difference (JND) to quantify level-dependent changes in the salience of the tonal signal. As a physiological correlate, we investigated late auditory evoked potentials (LAEPs) with electroencephalography (EEG). The results showed that the intensity JNDs were equal at the same physical target tone level, regardless of the presence or absence of masking release. Estimated salience was correlated with the amount of masking release. However, salience measures across conditions converged with the target tone level above 70 dB SPL. For the LAEPs, the P2 amplitudes were more closely linked to behavioral measures than the N1 amplitudes. Both behavioral and electrophysiological measures suggest that the salience of a masked tone at supra-threshold levels is correlated with the amount of masking release.

neuroscience↗