A detection-theoretic framework for modeling informational masking.
Ontology highlight
ABSTRACT:
SUBMITTER: Lutfi RA
PROVIDER: S-EPMC3407140 | biostudies-other | 2012 Aug
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Our ability to detect target sounds in complex acoustic backgrounds is often limited not by the ear's resolution, but by the brain's information-processing capacity. The neural mechanisms and loci of this "informational masking" are unknown. We combined magnetoencephalography with simultaneous behavioral measures in humans to investigate neural correlates of informational masking and auditory perceptual awareness in the auditory cortex. Cortical responses were sorted according to whether or not target sounds were detected by the listener in a complex, randomly varying multi-tone background known to produce informational masking. Detected target sounds elicited a prominent, long-latency response (50-250 ms), whereas undetected targets did not. In contrast, both detected and undetected targets produced equally robust auditory middle-latency, steady-state responses, presumably from the primary auditory cortex. These findings indicate that neural correlates of auditory awareness in informational masking emerge between early and late stages of processing within the auditory cortex.
| S-EPMC2422852 | biostudies-literature
Project description:The effects of two types of auditory distracters (steady-state noise vs. four-talker babble) on visual-only speechreading accuracy were tested against a baseline (silence) in 23 participants with above-average speechreading ability. Their task was to speechread high frequency Swedish words. They were asked to rate their own performance and effort, and report how distracting each type of auditory distracter was. Only four-talker babble impeded speechreading accuracy. This suggests competition for phonological processing, since the four-talker babble demands phonological processing, which is also required for the speechreading task. Better accuracy was associated with lower self-rated effort in silence; no other correlations were found.
| S-EPMC4068195 | biostudies-literature
Project description:In recent years there has been growing interest in masking that cannot be attributed to interactions in the cochlea-so--called informational masking (IM). Similarity in the acoustic properties of target and masker and uncertainty regarding the masker are the two major factors identified with IM. These factors involve quite different manipulations of signals and are believed to entail fundamentally different processes resulting in IM. Here, however, evidence is presented that these factors affect IM through their mutual influence on a single factor-the information divergence of target and masker given by Simpson-Fitter's da [Lutfi et al. (2012). J. Acoust. Soc. Am. 132, EL109-113]. Four experiments are described involving multitone pattern discrimination, multi-talker word recognition, sound-source identification, and sound localization. In each case standard manipulations of masker uncertainty and target-masker similarity (including the covariation of target-masker frequencies) are found to have the same effect on performance provided they produce the same change in da. The function relating d(') performance to da, moreover, appears to be linear with constant slope across listeners. The overriding dependence of IM on da is taken to reflect a general principle of perception that exploits differences in the statistical structure of signals to separate figure from ground.
| S-EPMC3765281 | biostudies-other
Project description:The degree of similarity between signal and masker in informational masking paradigms has been hypothesized to contribute to informational masking. The present study attempted to quantify "similarity" using a discrimination task. Listeners discriminated various signal stimuli from a multitone complex and then detected the presence of those signals embedded in a multitone informational masker. Discriminability negatively correlated with detection threshold in an informational masking experiment, indicating that similarity between signal and the masker quality contributed to informational masking. These results suggest a method for specifying relevant signal attributes in informational masking paradigms involving similarity manipulations.
| S-EPMC3117891 | biostudies-other
Project description:ObjectivesThis study aimed to evaluate the informational component of speech-on-speech masking. Speech perception in the presence of a competing talker involves not only informational masking (IM) but also a number of masking processes involving interaction of masker and target energy in the auditory periphery. Such peripherally generated masking can be eliminated by presenting the target and masker in opposite ears (dichotically). However, this also reduces IM by providing listeners with lateralization cues that support spatial release from masking (SRM). In tonal sequences, IM can be isolated by rapidly switching the lateralization of dichotic target and masker streams across the ears, presumably producing ambiguous spatial percepts that interfere with SRM. However, it is not clear whether this technique works with speech materials.DesignSpeech reception thresholds (SRTs) were measured in 17 young normal-hearing adults for sentences produced by a female talker in the presence of a competing male talker under three different conditions: diotic (target and masker in both ears), dichotic, and dichotic but switching the target and masker streams across the ears. Because switching rate and signal coherence were expected to influence the amount of IM observed, these two factors varied across conditions. When switches occurred, they were either at word boundaries or periodically (every 116 msec) and either with or without a brief gap (84 msec) at every switch point. In addition, SRTs were measured in a quiet condition to rule out audibility as a limiting factor.ResultsSRTs were poorer for the four switching dichotic conditions than for the nonswitching dichotic condition, but better than for the diotic condition. Periodic switches without gaps resulted in the worst SRTs compared to the other switch conditions, thus maximizing IM.ConclusionsThese findings suggest that periodically switching the target and masker streams across the ears (without gaps) was the most efficient in disrupting SRM. Thus, this approach can be used in experiments that seek a relatively pure measure of IM, and could be readily extended to translational research.
| S-EPMC6856419 | biostudies-literature
Project description:To hear out a conversation against other talkers listeners overcome energetic and informational masking. Largely attributed to top-down processes, information masking has also been demonstrated using unintelligible speech and amplitude-modulated maskers suggesting bottom-up processes. We examined the role of speech-like amplitude modulations in information masking using a spatial masking release paradigm. Separating a target talker from two masker talkers produced a 20 dB improvement in speech reception threshold; 40% of which was attributed to a release from informational masking. When across frequency temporal modulations in the masker talkers are decorrelated the speech is unintelligible, although the within frequency modulation characteristics remains identical. Used as a masker as above, the information masking accounted for 37% of the spatial unmasking seen with this masker. This unintelligible and highly differentiable masker is unlikely to involve top-down processes. These data provides strong evidence of bottom-up masking involving speech-like, within-frequency modulations and that this, presumably low level process, can be modulated by selective spatial attention.
| S-EPMC4345314 | biostudies-other
Project description:Suppressing unwanted background sound is crucial for aural communication. A particularly disruptive type of background sound, informational masking (IM), often interferes in social settings. However, IM mechanisms are incompletely understood. At present, IM is identified operationally: when a target should be audible, based on suprathreshold target/masker energy ratios, yet cannot be heard because target-like background sound interferes. We here confirm that speech identification thresholds differ dramatically between low- vs. high-IM background sound. However, speech detection thresholds are comparable across the two conditions. Moreover, functional near infrared spectroscopy recordings show that task-evoked blood oxygenation changes near the superior temporal gyrus (STG) covary with behavioral speech detection performance for high-IM but not low-IM background sound, suggesting that the STG is part of an IM-dependent network. Moreover, listeners who are more vulnerable to IM show increased hemodynamic recruitment near STG, an effect that cannot be explained based on differences in task difficulty across low- vs. high-IM. In contrast, task-evoked responses near another auditory region of cortex, the caudal inferior frontal sulcus (cIFS), do not predict behavioral sensitivity, suggesting that the cIFS belongs to an IM-independent network. Results are consistent with the idea that cortical gating shapes individual vulnerability to IM.
| S-EPMC8339305 | biostudies-literature
Project description:This study examined the degree to which increasing the number of signal presentations provides children with a release from informational masking. Listeners were younger children (5-7 years), older children (8-10 years), and adults. Detection thresholds were measured for a sequence of repeating 50-ms bursts of a 1000-Hz pure-tone signal embedded in a sequence of 10- and 50-ms bursts of a random-frequency, two-tone masker. Masker bursts were played at an overall level of 60-dB sound pressure level in each interval of a two-interval, forced choice adaptive procedure. Performance was examined for conditions with two, four, five, and six signal bursts. Regardless of the number of signal bursts, thresholds for most children were higher than thresholds for most adults. Despite developmental effects in informational masking, however, masked threshold decreased with additional signal bursts by a similar amount for younger children, older children, and adults. The magnitude of masking release for both groups of children and for adults was inconsistent with absolute energy detection. Instead, increasing the number of signal bursts appears to aid children in the perceptual segregation of the fixed-frequency signal from the random-frequency masker as has been previously reported for adults [Kidd, G., et al. (2003). J. Acoust. Soc. Am. 114, 2835-2845].
| S-EPMC2736737 | biostudies-other
Project description:Human listeners can follow the voice of one speaker while several others are talking at the same time. This process requires segregating the speech streams from each other and continuously directing attention to the target stream. We investigated the functional brain networks underlying this ability. Two speech streams were presented simultaneously to participants, who followed one of them and detected targets within it (target stream). The loudness of the distractor speech stream varied on five levels: moderately softer, slightly softer, equal, slightly louder, or moderately louder than the attended. Performance measures showed that the most demanding task was the moderately softer distractors condition, which indicates that a softer distractor speech may receive more covert attention than louder distractors and, therefore, they require more cognitive resources. EEG-based measurement of functional connectivity between various brain regions revealed frequency-band specific networks: (1) energetic masking (comparing the louder distractor conditions with the equal loudness condition) was predominantly associated with stronger connectivity between the frontal and temporal regions at the lower alpha (8-10 Hz) and gamma (30-70 Hz) bands; (2) informational masking (comparing the softer distractor conditions with the equal loudness condition) was associated with a distributed network between parietal, frontal, and temporal regions at the theta (4-8 Hz) and beta (13-30 Hz) bands. These results suggest the presence of distinct cognitive and neural processes for solving the interference from energetic vs. informational masking.
| S-EPMC6465330 | biostudies-literature
Project description:Given the potential wealth of insights in personal data the big databases can provide, many organizations aim to share data while protecting privacy by sharing de-identified data, but are concerned because various demonstrations show such data can be re-identified. Yet these investigations focus on how attacks can be perpetrated, not the likelihood they will be realized. This paper introduces a game theoretic framework that enables a publisher to balance re-identification risk with the value of sharing data, leveraging a natural assumption that a recipient only attempts re-identification if its potential gains outweigh the costs. We apply the framework to a real case study, where the value of the data to the publisher is the actual grant funding dollar amounts from a national sponsor and the re-identification gain of the recipient is the fine paid to a regulator for violation of federal privacy rules. There are three notable findings: 1) it is possible to achieve zero risk, in that the recipient never gains from re-identification, while sharing almost as much data as the optimal solution that allows for a small amount of risk; 2) the zero-risk solution enables sharing much more data than a commonly invoked de-identification policy of the U.S. Health Insurance Portability and Accountability Act (HIPAA); and 3) a sensitivity analysis demonstrates these findings are robust to order-of-magnitude changes in player losses and gains. In combination, these findings provide support that such a framework can enable pragmatic policy decisions about de-identified data sharing.
| S-EPMC4373733 | biostudies-literature