Masking Level Difference Research Articles

Age-Related Listening Performance Changes Across Adulthood.

This study compares auditory processing performance across different decades of adulthood, including young adults and middle-aged individuals with normal hearing and no spontaneous auditory complaints. We assessed 80 participants with normal hearing, at least 10 years of education, and normal global cognition. The participants completed various auditory tests, including speech-in-noise, dichotic digits, duration, pitch pattern sequence, gap in noise, and masking level difference. In addition, we conducted working memory assessments and administered a questionnaire on self-perceived hearing difficulties. Our findings revealed significant differences in auditory test performance across different age groups, except for the masking level difference. The youngest group outperformed all other age groups in the speech-in-noise test, while differences in dichotic listening and temporal resolution emerged from the age of 40 and in temporal ordering from the age of 50. Moreover, higher education levels and better working memory test scores were associated with better auditory performance as individuals aged. However, the influence of these factors varied across different auditory tests. It is interesting that we observed increased self-reported hearing difficulties with age, even in participants without spontaneous auditory complaints. Our study highlights significant variations in auditory test performance, with noticeable changes occurring from age 30 and becoming more pronounced from age 40 onward. As individuals grow older, they tend to perceive more hearing difficulties. Furthermore, the impact of age on auditory processing performance is influenced by factors such as education and working memory.

Masking level differences under two different measurement conditions: A normative study of young adults.

The objective of this study was to determine the gender-specific normative values of masking level difference (MLD) in healthy young adults for two different measurement conditions. One hundred young adults between the ages of 19 and 25 were included. Tympanometry, pure tone audiometry, and MLD were performed. In the first MLD measurement condition, the threshold level where the signal was out of phase and the noise was in phase (SπNo) was subtracted from the threshold level where the signal and noise were in phase (SoNo). In the second MLD measurement condition, the threshold level where the signal was in phase and the noise was out of phase (SoNπ) was subtracted from the threshold level where the signal and noise were in phase (SoNo). The mean test scores were obtained in decibels. Comparisons were made in terms of gender and conditions. The mean MLD for SoNo-SπNo condition was 10.3±1.99dB. For SoNo-SoNπ condition, the mean MLD was 6.72±2.38dB. A significant difference was determined between the MLD under two different measurement conditions (p <.05). There was no significant difference in terms of gender (p >.05). Mean normative values of MLD test scores in gender-specific healthy young adults for two different measurement conditions are presented.

Monaural and binaural masking release with speech-like stimuli.

The relevance of comodulation and interaural phase difference 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. The target was a diotic or dichotic frequency-modulated tone following F2 trajectories. Results showed a small comodulation masking release, while the binaural masking level difference was comparable to previous findings. The data suggest that factors other than comodulation may play a dominant role in grouping frequency components in speech.

Binaural Interaction Component and Behavioral Auditory Processing in the Elderly with Hearing Loss: Preliminary Study

Purpose: The binaural interaction component (BIC) is presumed to reflect binaural hearing abilities, including spatial hearing. This study aims to record BIC amplitudes and examine their relationship with behavioral auditory tests.Methods: Nine elderly adults with hearing loss (eight males and one female) participated in this study. The BIC was derived from the wave V amplitude of the auditory brainstem response (ABR) and the N1-P2 amplitude of the auditory late latency response (ALR). Behavioral auditory processing tests, including sentence recognition scores, localization scores, and masking level difference, were obtained and analyzed with respect to electrophysiological BICs.Results: BICs were more reliably identified in ALR compared to ABR. The ALR BIC elicited by a 2,000 Hz tone burst showed a significant correlation with sentence recognition scores in both quiet and noise, as well as localization scores at 2,000 Hz. Other variables also demonstrated significant interrelationships.Conclusion: This study suggests that the ALR BIC elicited by a 2,000 Hz tone burst may be a key physiological component representing spatial hearing abilities in individuals with hearing loss. More robust conclusions can be drawn from future studies with larger sample sizes and more sophisticated designs.

Central Auditory Processing Abilities in Children with Non-Syndromic Cleft Lip/and Palate-a Behavioural Study.

The present study aimed to assess the central auditory processing abilities and working memory in children with non-syndromic cleft lip and palate (NSCLP) and to compare with the developed normative and craniofacially normal peers. Sixteen NSCLP children aged 7 to 12 years and fifteen craniofacially normal peers were recruited in this study. Speech perception in noise Kannada (SPIN-K), gap detection threshold (GDT), dichotic consonant-vowel (DCV), and masking level difference (MLD) tests were administered to assess various central auditory processing abilities. Working memory abilities were assessed by using forward-digit span and backward-digit span tests. The results showed significant differences in SPIN-K, dichotic CV, GDT, forward digit, and backward digit span scores between children with NSCLP and craniofacially normal peers. Thus, it can be concluded from the present study that children with NSCLP have a risk of developing auditory processing deficits. To conclude, assessment of central auditory processing abilities in children with NSCLP is recommended.

Examining the utility of near infrared light as pre-exposure therapy to mitigate temporary noise-induced hearing loss in humans.

This study sought to determine the effect of Occupational Safety and Health Administration (OSHA) compliant noise on auditory health and assess whether pre-noise near infrared (NIR) light therapy can mitigate the effects of noise exposure. Over four visits, participants (n = 30, NCT#: 03834714) with normal hearing completed baseline hearing health assessments followed by exposure to open ear, continuous pink noise at 94 dBA for 15 min. Immediately thereafter, post-noise hearing tests at 3000, 4000, and 6000 Hz and distortion product otoacoustic emissions (DPOAEs) were conducted along with the Modified Rhyme Test (MRT), Masking Level Difference Test (MLD), and Fixed Level Frequency Tests (FLFT) [collectively referred to as the Central and Peripheral Auditory Test Battery (CPATB)] to acquire baseline noise sensitivity profiles. Participants were then randomized to either Active or Sham NIR light therapy for 30 min binaurally to conclude Visit 1. Visit 2 (≥24 and ≤ 48 h from Visit 1) began with an additional 30-min session of Active NIR light therapy or Sham followed by repeat CPATB testing and noise exposure. Post-noise testing was again conducted immediately after noise exposure to assess the effect of NIR light therapy. The remaining visits were conducted following ≥2 weeks of noise rest in a cross-over design (i.e., those who had received Active NIR light therapy in Visits 1 and 2 received Sham therapy in Visits 3 and 4). Recovery hearing tests and DPOAEs were completed at the end of each visit. Participants experienced temporary threshold shifts (TTS) immediately following noise exposure, with a mean shift of 6.79 dB HL (±6.25), 10.61 dB HL (±6.89), and 7.30 dB HL (±7.25) at 3000, 4000, and 6000 Hz, respectively, though all thresholds returned to baseline at 3000, 4000, and 6000 Hz within 75 min of noise exposure. Paradoxically, Active NIR light therapy threshold shifts were statistically higher than Sham therapy at 3000 Hz (p = 0.04), but no other differences were observed at the other frequencies tested. An age sub-analysis demonstrated that TTS among younger adults were generally larger in the Sham therapy group versus Active therapy, though this was not statistically different. There were no differences in CPATB test results across Active or Sham groups. Finally, we observed no changes in auditory function or central processing following noise exposure, suggestive of healthy and resilient inner ears. In this study, locally administered NIR prior to noise exposure did not induce a significant protective effect in mitigating noise-induced TTS. Further exploration is needed to implement effective dosage and administration for this promising otoprotective therapy.

Dynamic Spatial Auditory Processing in the Elderly.

One of the most obvious functional effects of aging on the cognitive and processing processes of spatial hearing is the localization problem and the disorder of speech perception in noise. The purpose of the present study is to investigate the performance of dynamic spatial auditory processing in the elderly. This descriptive and analytical study was conducted on 60 young participants aged from18 to 25 years old and 60 elderly participants aged from 60 to 75 old years, using speech, spatial, and qualities of hearing scale (SSQ) questionnaire, binaural masking level difference (BMLD) and dynamic quick speech in noise (DS-QSIN) tests. Comparing the average scores of the tests and the questionnaire using the independent t test showed a significant difference between the two groups (p < 0.001). It was also found that gender had no effect on the results (p > 0.05). Aging is accompanied by different structural and functional changes in the auditory central nervous system, which leads to a decrease in speech perception in challenging listening environments, as well as a decrease in sound localization abilities, due to the reduction of temporal and spectral information. This problem affects the determination of the source of sound and the spatial cognition of the elderly and leads to a disturbance in the awareness of the auditory environment. Therefore, auditory rehabilitation programs can cause the improvement of spatial auditory processing performance and improve speech perception in noise in the elderly.

A spatial digit task for assessing binaural function in individuals with hearing loss

Spatial hearing is crucial in occupational tasks, yet until 2019, US Army fitness-for-duty requirements only considered hearing thresholds in the better ear. The regulation change introduced the Military Operational Hearing Test (MOHT) for those with worse-ear thresholds exceeding 40 dB HL at 0.5 or 1 kHz, or 60 dB HL at 2 kHz. This led to the development of the Spatial Digit Test (SDT) to assess binaural function in individuals with poor hearing in one ear but sufficiently good hearing in the other ear to pass a speech-in-noise test. The SDT involves digit pairs presented with Interaural Time Delays (ITDs) of +/−800 μs. Two studies were conducted: a validation study with over 200 individuals, and a verification study with more than 130 undergoing MOHT exams. Results show that individuals with normal auditory thresholds perform very well on the SDT, with about 95% correctly identifying at least 8 digits and 75% correctly identifying all 10. In contrast, only about 50% of individuals with monaural losses who took the SDT as part of the MOHT identified 8 or more digits. Results of the SDT were correlated both with subjective hearing complaints and with the Binaural Masking Level Difference. In conclusion, the SDT proves valuable for identifying individuals struggling using ITD cues to segregate and localize simultaneously presented speech signals.

Age-Related Deficits in Binaural Hearing: Contribution of Peripheral and Central Effects.

Pure-tone audiograms often poorly predict elderly humans' ability to communicate in everyday complex acoustic scenes. Binaural processing is crucial for discriminating sound sources in such complex acoustic scenes. The compromised perception of communication signals presented above hearing threshold has been linked to both peripheral and central age-related changes in the auditory system. Investigating young and old Mongolian gerbils of both sexes, an established model for human hearing, we demonstrate age-related supra-threshold deficits in binaural hearing using behavioral, electrophysiological, anatomical, and imaging methods. Binaural processing ability was measured as the binaural masking level difference (BMLD), an established measure in human psychophysics. We tested gerbils behaviorally with "virtual headphones," recorded single-unit responses in the auditory midbrain and evaluated gross midbrain and cortical responses using positron emission tomography (PET) imaging. Furthermore, we obtained additional measures of auditory function based on auditory brainstem responses, auditory-nerve synapse counts, and evidence for central inhibitory processing revealed by PET. BMLD deteriorates already in middle-aged animals having normal audiometric thresholds and is even worse in old animals with hearing loss. The magnitude of auditory brainstem response measures related to auditory-nerve function and binaural processing in the auditory brainstem also deteriorate. Furthermore, central GABAergic inhibition is affected by age. Because the number of synapses in the apical turn of the inner ear was not reduced in middle-aged animals, we conclude that peripheral synaptopathy contributes little to binaural processing deficits. Exploratory analyses suggest increased hearing thresholds, altered binaural processing in the brainstem and changed central GABAergic inhibition as potential contributors.

Assessment of Central Auditory Processing in Children Using a Novel Tablet-Based Platform: Application for Low- and Middle-Income Countries.

Evaluate whether a portable, tablet-based central auditory processing (CAP) test system using native language training videos and administered by minimally trained community health workers can produce CAP results comparable to previously published norms. Our secondary aim was to determine subject parameters that influence test results. Cross-sectional study. Community-based settings in Chontales, Nicaragua, New Hampshire, and Florida. English- and/or Spanish-speaking children and adolescents (n = 245; average age, 12.20 yr; range, 6-18 yr). Completion of the following tests with responses comparable to published norms: Pure-tone average (PTA), gap detection threshold (GDT), fixed-level frequency threshold, masking level difference (MLD), Hearing in Noise Test (HINT), Dichotic Digits Test (DDT), and Frequency Pattern Recognition (FPR) test. GDT, HINT, and DDT had comparable results to previously published normative values. MLD and FPR results differed compared with previously published normative values. Most CAP tests (MLD, GDT, HINT) results were independent of age and PTA (p = 0.1-0.9). However, DDT was associated with age and PTA (p < 0.0001). Pediatric CAP testing can be successfully completed in remote low- and middle- income country environments using a tablet-based platform without the presence of an audiologist. Performance on DDT improved with age but deteriorated with hearing loss. Further investigation is warranted to assess the variability of FPR.

Associations Between Auditory Working Memory, Self-Perceived Listening Effort, and Hearing Difficulty in Adults With Mild Traumatic Brain Injury.

Mild traumatic brain injury (TBI) can have persistent effects in the auditory domain (e.g., difficulty listening in noise), despite individuals having normal pure-tone auditory sensitivity. Individuals with a history of mild TBI often perceive hearing difficulty and greater listening effort in complex listening situations. The purpose of the present study was to examine self-perceived hearing difficulty, listening effort, and performance on an auditory processing test battery in adults with a history of mild TBI compared with a control group. Twenty adults ages 20 to 53 years old participated divided into a mild TBI (n = 10) and control group (n = 10). Perceived hearing difficulties were measured using the Adult Auditory Processing Scale and the Hearing Handicap Inventory for Adults. Listening effort was measured using the National Aeronautics and Space Administration-Task Load Index. Listening effort ratings were obtained at baseline, after each auditory processing test, and at the completion of the test battery. The auditory processing test battery included (1) dichotic word recognition, (2) the 500-Hz masking level difference, (3) the Listening in Spatialized Noise-Sentences test, and (4) the Word Auditory Recognition and Recall Measure (WARRM). Results indicated that individuals with a history of mild TBI perceived significantly greater degrees of hearing difficulty and listening effort than the control group. There were no significant group differences on two of the auditory processing tasks (dichotic word recognition or Listening in Spatialized Noise-Sentences). The mild TBI group exhibited significantly poorer performance on the 500-Hz MLD and the WARRM, a measure of auditory working memory, than the control group. Greater degrees of self-perceived hearing difficulty were significantly associated with greater listening effort and poorer auditory working memory. Greater listening effort was also significantly associated with poorer auditory working memory. Results demonstrate that adults with a history of mild TBI may experience subjective hearing difficulty and listening effort when listening in challenging acoustic environments. Poorer auditory working memory on the WARRM task was observed for the adults with mild TBI and was associated with greater hearing difficulty and listening effort. Taken together, the present study suggests that conventional clinical audiometric battery alone may not provide enough information about auditory processing deficits in individuals with a history of mild TBI. The results support the use of a multifaceted battery of auditory processing tasks and subjective measures when evaluating individuals with a history of mild TBI.

The Effects of a Home Personal Computer-based Auditory Training Program on the Binaural Listening Skills of Children With Specific Learning Disability: A Protocol for a Randomized Clinical Trial

Background and Objectives: A high prevalence of central auditory processing disorders has been reported in children with learning disabilities. One of the crucial auditory processing disorders in these children is a binaural processing problem. Binaural hearing leads to improved auditory performance in noisy situations. This research aims to develop an auditory training program based on binaural interaction at the brainstem level and to investigate its effect on the binaural listening skills of children with a specific learning disability. Methods: After developing the rehabilitation program and determining its validity, this intervention study is conducted in three stages. The first stage includes baseline assessments, the second stage includes the implementation of rehabilitation intervention and the third stage consists of the re-implementation of the tests of the first stage once immediately after intervention and then once after 45 days of training. Masking level differences (MLD), Persian auditory recognition of words in noise (PARWIN), and binaural speech-auditory brainstem response (Speech-ABR) tests are the primary outcome measures. Persian randomized dichotic digits test (PRDDT), Persian pediatric competing word test (PPCWT), Persian pediatric competing sentences test (PPCST), and Persian version of the auditory processing disorder questionnaire (APDQ-P) were included as secondary outcome measures. The sample size in each intervention and control group was 15 people and the duration of training was 3 months. Conclusion: Considering the importance of brainstem function in binaural hearing, it is recommended to investigate the effectiveness of the developed binaural interaction training program in improving hearing in background noise in children with specific learning disabilities.

Low-frequency limit for binaural timing cues

Sound localization uses both interaural time differences (ITDs) and interaural level differences (ILDs). The ITD cue has a high-frequency boundary at 1500 Hz but is assumed to be limited only by the lowest audible frequency. We tested whether there is a low-frequency boundary for the ITD cue. Nineteen young, normal-hearing subjects participated in four experiments, in which 500-ms, 70-phon pure tones with various binaural cues were presented as a function of frequency from 62.5 to 2000 Hzin octave steps. The 70-phon level assured that audibility did not confound performance. Experiment 1 served as a control, in which a 10-dB ILD cue produced ∼90% correct lateralization at all frequencies. Experiment 2 measured lateralization accuracy with a 90-degree ITD cue, Experiment 3 measured the just-noticeable-difference from a 0-degree ITD standard, while Experiment 4 measured the binaural masking level difference in white noise. As expected, the listeners could not use the timingcue to perform these binaural tasks at 2000 Hz; Surprisingly, they showed significantly poorer performance at 62.5 Hz than mid frequencies. The band-pass characteristic result suggested a low-frequency boundary for binaural timing cues. This low boundary is not due to audibility but likely physical or physiological processes in the ear.

The Impact of Traumatic Brain Injury on Binaural Processing in Young and Middle-Age Adults.

This study examined the impact of traumatic brain injury (TBI) on self-perceived hearing and suprathreshold binaural processing in young and middle-age adults. Ninety-three adults with normal hearing (thresholds ≤ 25 dB HL, 250-4000 Hz) participated in one of four groups: 38 young adults, 23 young adults with TBI, 16 middle-age adults, and 16 middle-age adults with TBI. Self-perceived hearing difficulty was measured via questionnaires. Binaural processing was measured using dichotic word recognition, the Listening in Spatialized Noise-Sentences Test (LiSN-S), and the 500-Hz masking level difference (MLD). For each participant, a composite binaural processing (CBP) score was calculated to obtain a global metric of binaural processing performance. The CBP was composed of six measures from the three behavioral tests, including the S0N0 and SπN0 thresholds from the 500-Hz MLD, the low- and high-cue speech recognition thresholds from the LiSN-S, and the free and directed recall ear advantages from the dichotic word test. The middle-age TBI group reported significantly greater degrees of self-perceived hearing difficulty than the other groups. On average, the middle-age TBI group performed poorer on the individual binaural processing tests; however, the differences were significant for the S0N0 and SπN0 MLD thresholds only. Results for the global metric of binaural processing revealed significantly poorer CBP scores for the middle-age TBI group compared to the other groups. Results demonstrate that both age and a positive history of TBI contributed to deficits in suprathreshold binaural processing. Middle-age adults with a history of TBI are at risk for experiencing presenescent deficits in suprathreshold binaural processing deficits, despite having clinically normal hearing.

A Survey on Screening and Diagnostic Criteria of Auditory Processing Disorders in India.

The current study aimed to determine the criteria used for screening and diagnosing cases with central auditory processing disorders (CAPD) in India. A cross-sectional questionnaire-based survey design was used in the present study. A questionnaire was developed to determine the criteria used for screening and diagnosing CAPD across clinics in India. Responses were obtained from 83 participants from all over India. Results indicated that 78% of respondents were currently doing CAPD evaluation. In that, the majority of respondents (63%) had a predetermined minimum battery that was relatively adaptable depending on the case history and age of the patient. In screening, most respondents used a screening questionnaire (SCAP, 75%) and a screening test (STAP, 60%). In the diagnostic protocol, the most used tests by the respondents were masking level difference (MLD), repetition of words (RW), gap detection test (GDT), pitch pattern test (PPT), speech perception in noise (SPIN), digit span test (DST), dichotic digit test (DDT), binaural fusion test (BFT), auditory brainstem response (ABR), dichotic CV test (DCVT), and duration pattern test (DPT). The current study's result will help professionals choose the minimum test battery for diagnosing CAPD.

Binaural masking level difference for pure tone signals

The binaural masking level difference (BMLD) is a psychoacoustic method to determine binaural interaction and central auditory processes. The BMLD is the difference in hearing thresholds in homophasic and antiphasic conditions. The duration, phase and frequency of the stimuli can affect the BMLD. The main aim of the study is to evaluate the BMLD for stimuli of different durations and frequencies which could also be used in future electrophysiological studies. To this end we developed a GUI to present different frequency signals of variable duration and determine the BMLD. Three different durations and five different frequencies are explored. The results of the study confirm that the hearing threshold for the antiphasic condition is lower than the hearing threshold for the homophasic condition and that differences are significant for signals of 18ms and 48ms duration. Future objective binaural processing studies will be based on 18ms and 48ms stimuli with the same frequencies as used in the current study.

Efficient Estimation of the Binaural Masking Level Difference Using a Technique Based on Manual Audiometry.

The Masking Level Difference (MLD) has been used for decades to evaluate the binaural listening advantage. Although originally measured using Bekesy audiometry, the most common clinical use of the MLD is the CD-based Wilson 500-Hz technique with interleaved N0S0 and N0Sπ components. Here, we propose an alternative technique based on manual audiometry as a faster way of measuring the MLD. The article describes the advantages to this administration technique and evaluates if it is a viable alternative for the Wilson technique. Data were retrospectively analyzed on 264 service members (SMs). All SMs completed both the Wilson and Manual MLDs. Descriptive and correlational statistics were applied to evaluate the comparisons between the two techniques and highlight the differences. Equivalence measures were also completed to compare the tests using a standardized cutoff score. Analyses were also made to compare both techniques to subjective and objective measures of hearing performance. Moderate to high positive correlations were determined between Wilson and Manual measures of each threshold (N0Sπ and N0S0). Although the Manual and Wilson MLD techniques produced significantly different thresholds, simple linear transformations can be used to obtain approximately equivalent scores on the two tests, and agreement was high for using these transformed scores to identify individuals with substantial MLD deficits. Both techniques had moderate test-retest reliability. The Manual MLD and components had stronger correlations to the subjective and objective hearing measures than the Wilson. The Manual technique is a faster method for obtaining MLD scores that is just as reliable as the CD-based Wilson test. With the significant reduction in assessment time and comparable results, the Manual MLD is a viable alternative for direct use in the clinic.

Avaliação comportamental do processamento auditivo central em mulheres no climatério

ABSTRACT Purpose To compare the central auditory abilities of climacteric women, with and without hormone replacement therapy. Methods Observational study, performed with climacteric women with and without hormone replacement therapy. Sound localization tests were performed in five directions; Sequential Verbal Memory Test; Sequential Memory Test for Nonverbal Sounds; Duration Pattern Test; Random Gap Detection Test); Masking Level Difference; Dichotic Digit Test and Speech With White Noise Test and the questionnaire “Informal Fatigue Assessment” was applied. Results The differences pointed out revealed the biased difference that occurs due to higher average performance in the group with TH compared to the group without TH for TMSnV. In the TLS, TMSN, RGDT and MLD tests, the group with HT presented quantitatively better results. Conclusion Climacteric women, with and without hormone therapy, have central auditory processing disorder involving the auditory skills of sound localization, simple and complex temporal ordering, background figure, temporal resolution and binaural interaction. However, women in the hormone therapy group performed better in simple temporal ordering.

Habilidades auditivas em adultos jovens com e sem percepção de zumbido: um estudo de comparações

ABSTRACT Purpose Objective: To analyze auditory information processing responses in young adult subjects with tinnitus disorder. Methods A descriptive and quantitative study was conducted, involving 36 subjects aged between 19 and 35 years. The subjects were divided into two groups: Group 1 (20 subjects with chronic tinnitus) and Group 2 (16 subjects without tinnitus). All participants underwent medical history assessment, Visual Inspection of the External Auditory Canal, Pure-Tone Audiometry, Speech Audiometry, Acoustic Immittance Measures, and used Behavioral Central Auditory Processing Tests as an evaluation tool - Dichotic Digits Test (TDD), Frequency Pattern Test, Speech in Noise, Masking Level Difference, and Gap in Noise (GIN). Results Statistically significant differences were found between the groups for TDD responses in the left ear and for GIN in both ears. Conclusion Young adults with chronic tinnitus exhibit impairments in binaural integration and temporal resolution skills.

Responses to dichotic tone-in-noise stimuli in the inferior colliculus.

Human listeners are more sensitive to tones embedded in diotic noise when the tones are out-of-phase at the two ears (N0Sπ) than when they are in-phase (N0S0). The difference between the tone-detection thresholds for these two conditions is referred to as the binaural masking level difference (BMLD) and reflects a benefit of binaural processing. Detection in the N0Sπ condition has been explained in modeling studies by changes in interaural correlation (IAC), but this model has only been directly tested physiologically for low frequencies. Here, the IAC-based hypothesis for binaural detection was examined across a wide range of frequencies and masker levels using recordings in the awake rabbit inferior colliculus (IC). IAC-based cues were strongly correlated with neural responses to N0Sπ stimuli. Additionally, average rate-based thresholds were calculated for both N0S0 and N0Sπ conditions. The rate-based neural BMLD at 500 Hz matched rabbit behavioral data, but the trend of neural BMLDs across frequency differed from that of humans.