The impact of tinnitus on cognitive performance in normal-hearing individuals.

The aim of this study was to investigate whether the previously reported differences in cognitive performance as assessed using a Stroop paradigm between individuals with and without tinnitus is present in normal-hearing individuals

Reading comprehension in quiet and in noise : Effects on immediate and delayed recall in relation to tinnitus and high-frequency hearing thresholds

Background: A common complaint by people with tinnitus is that they experience that the tinnitus causes attention and concentration problems. Previous studies have examined how tinnitus influences cognitive performance on short and intensive cognitive tasks but without proper control of hearing status. Purpose: To examine the impact tinnitus and high-frequency hearing thresholds have on reading comprehension in quiet and in background noise. Research Design: A between-group design with matched control participants. Study Sample: One group of participants with tinnitus (n 5 20) and an age and gender matched control group without tinnitus (n 5 20) participated. Both groups had normal hearing thresholds (20 dB HL at frequencies 0.125 to 8 kHz). Data Collection and Analysis: Measurements were made assessing hearing thresholds and immediate and delayed recall using a reading comprehension test in quiet and in noise. All participants completed the Swedish version of the Hospital Anxiety and Depression Scale, and participants with tinnitus also completed the Tinnitus Questionnaire. Results: The groups did not differ in immediate nor delayed recall. Accounting for the effect of age, a significant positive correlation was found between best ear high-frequency pure tone average (HF-PTA; 10000, 12500, and 14000 Hz) and the difference score between immediate and delayed recall in noise. Conclusions: Tinnitus seems to have no effect on immediate and delayed recall in quiet or in background noise when hearing status is controlled for. The detrimental effect of background noise on the processes utilized for efficient encoding into long-term memory is larger in participants with better HF-PTA. More specifically, when reading in noise, participants with better HF-PTA seem to recall less information than participants with poorer HF-PTA

The impact of tinnitus on working memory capacity

Objective: To determine if tinnitus was related to working memory (WM) in adults and if tinnitus handicap was related to WM in adults with tinnitus.Design: Two groups, cross-sectional design.Study samples: 76 adults forming a tinnitus group (n = 38) and a control group (n = 38). Each group included 19 adults with normal hearing and 19 adults with hearing loss matched for age, sex and educational backgrounds. All participants completed the visual\ua0n-back test; pure tone audiometry (0.125–16 kHz); and the Hospital Anxiety and Depression Scale (HADS). Tinnitus sufferers also completed the Tinnitus Handicap Inventory (THI).Results: For all participants, tinnitus was not related to WM scores when corrected for hearing thresholds, anxiety, and depression. The corrections for best ear high-frequency pure-tone average hearing threshold (BEHFPTA: 10, 12.5, 14 and 16 kHz) were significant. For tinnitus sufferers, THI was related to WM scores in the easiest\ua0n-back condition, and BEHFPTA was related to WM scores in the easiest and the hardest\ua0n-back condition.Conclusion: Tinnitus was not related to WM scores. Tinnitus handicap was related to some WM scores in tinnitus sufferers. Further investigation of the possible relationship between high-frequency hearing and WM is warranted

Increasing cognitive interference modulates the amplitude of the auditory brainstem response

Despite the presence of efferent neural pathways from the cortex to brainstem, evidence for cognitive inhibition and sensory gating on the auditory brainstem has been mixed. Some previous studies have suggested auditory brainstem responses (ABR) can be affected by cognitive load whereas others have not.The present study explores if the ABR recorded from adults with normal hearing was affected by increased cognitive load involving cognitive interference.Within-subject repeated measures.Twenty young adults with normal hearing (ten females and ten males, aged 21-26 yr).ABRs were collected with and without cognitive load (a visual Stroop task). Two measures of cognitive interference, that is, the ability to suppress task-irrelevant input, were derived from the performance on the Stroop task.No main effect of cognitive load on ABR wave V amplitudes was found. Participants with higher cognitive interference showed increased response times and larger decreases in ABR wave V amplitudes from the no cognitive load to cognitive load conditions.The present study showed that ABR wave V amplitudes did not change with increased overall cognitive load (cognitive load with and without cognitive interference), but ABR amplitude was related to cognitive interference. Increased cognitive load in the form of increased cognitive interference could trigger cognitive inhibition and/or sensory gating to suppress the processing of task-irrelevant information at the level of the brainstem. This suppression could present as reduced ABR wave V amplitudes

Listening effort : Order effects and core executive functions

Background: Listening effort seems to depend on input-related listening demands and several factors internal to the individual listener. Input-related demands may be listening in noise compared with listening in quiet, and internal factors may be cognitive functions. Purpose: The purpose was to apply measures of listening effort and perceived listening effort in participants with normal hearing, to determine if there are any presentation order effects, and to explore the relationship between listening effort measured as accuracy, response times, efficiency of information encoding into long-term memory, perceived listening effort, and core executive functions. Research design: A within-subject design with repeated measures was used and a study of relationships between variables was made. Study sample: Thirty-two healthy adults with normal hearing. Data collection and analysis: Participants were tested individually by a listening task using a dual-task paradigm. The listening task was performed in quiet and in multitalker babble noise at 10 dB signal-to-noise ratio (SNR). Perceived listening effort and core executive functions (working memory, inhibitory control, and cognitive flexibility) were also assessed. Results: The measures of listening effort (correct responses, response times, and immediate and delayed listening comprehension) failed to demonstrate increased listening effort in multitalker babble noise (10 dB SNR) compared with quiet, although a significant test order effect was seen for correct responses indicating that participants who first listened in noise did not improve in quiet. Perceived listening effort increased significantly in noise compared with quiet. No relationship was found between measures of listening effort and ratings of perceived listening effort. Working memory and cognitive flexibility were not related to ratings of perceived listening effort. In contrast, better inhibitory control was related to higher ratings in both quiet and in noise. Conclusions: It is possible that the SNR and measures used were not as sensitive as required to measure listening effort behaviorally. In the present experimental setup, prior noise exposure impedes the beneficial effects of performing a task in quiet. Self-reports seem to provide a valid measure of perceived listening effort that is related to the individual's inhibitory control. The present findings suggest that participants with better inhibitory control are more susceptible to the task demand level both in quiet and in noise

Hearing thresholds and cognitive flexibility in young healthy individuals with normal hearing

Objective: Pure tone audiometry may seem to be a relatively easy task for the participant but it may involve cognitive as well as sensory abilities. The aim of this study is to examine the relationship between hearing thresholds in the frequency range 0.125–8 kHz and the core executive function cognitive flexibility in healthy individuals with normal hearing. Design: Experimental study measuring correlations between different pure-tone hearing threshold measures and cognitive flexibility. Pure tone air conduction audiometry (frequencies 0.125–8.0 kHz) and two tests of cognitive flexibility (information updating and shifting ability) were conducted. Study sample: Seventy-two subjects (aged between 21 and 36) with normal hearing (<20 dB HL) for the tested frequencies. Results: Four measures of average pure tone hearing thresholds were negatively correlated with cognitive flexibility. Conclusions: Pure-tone air conduction hearing thresholds seem to be related to cognitive flexibility in healthy individuals with normal hearing

Extended high-frequency pure tone hearing thresholds and core executive functions

Objective: To examine the relationship between extended high-frequency pure tone hearing thresholds (frequencies 10 to 14 kHz) and working memory capacity (WMC), inhibitory control, and cognitive flexibility. Design: Experimental study measuring correlations between different high-frequency hearing threshold measures and cognitive measures. Study: Pure tone audiometry was assessed in the extended high-frequency (frequencies 10, 12.5 and 14 kHz). Subjects were also tested regarding WMC, inhibitory control (response inhibition), and cognitive flexibility (information updating and shifting ability). Sample: Forty-three subjects between 20 and 29 years old with normal hearing (≤ 20 dB HL) in the frequency range between 0.125 to 8 kHz. Results: No significant correlations were seen between high-frequency hearing thresholds defined as average best and worst ear high-frequency hearing thresholds and the cognitive measures. Differences between the best and the worst ear showed significant negative correlations with inhibitory control and global executive function (combination score for WMC, inhibitory control and cognitive flexibility). Conclusions: The present study suggests that global executive functions, more specifically response inhibition, and hearing threshold asymmetry in the extended high-frequency range are interrelated

Extended High Frequency Hearing, but Not Tinnitus, Is Associated With Every-Day Cognitive Performance

Research into the potential associations between tinnitus and cognition has investigated specific cognitive domains in laboratory settings despite adults with tinnitus reporting broad cognitive difficulties in every-day life. To address this limitation, the present study compared performance and perceived exertion on a visual office-like task in 38 adults with tinnitus (19 with normal hearing and 19 with hearing loss) and 38 adults without tinnitus (19 with normal hearing and 19 with hearing loss) matched for age, sex and educational background. All participants were also assessed for hearing, anxiety and depression, and participants with tinnitus were also assessed for tinnitus handicap. No associations were found between presence of tinnitus and cognitive performance (mean total rate correct score on the visual office-like task being 2.9 for the tinnitus group, 2.8 for the control group, p = 0.612) and perceived exertion (mean ratings of perceived exertion on the Borg CR10-scale being 5.8 for the tinnitus group, 6.5 for the control group, p = 0.063) on the visual office-like task when corrected for standard (0.125 to 8 kHz) and extended high frequency (10 to 16 kHz) hearing thresholds, anxiety, and depression. The correction for extended high frequency average (10, 12.5, 14, and 16 kHz) hearing threshold was significant for performance ( p = 0.009) but not perceived exertion on the visual office-like task. Overall, the results showed extended high frequency hearing, but not tinnitus, was associated with every-day cognitive performance. This indicates clinical testing of hearing thresholds above 8 kHz could support clinicians' identification and management of cognitive difficulties. One management method suggested by the current findings would include provision of auditory stimulation at frequencies exceeding the frequency response of many current hearing aids

The impact of tinnitus on n-back performance in normal hearing individuals

Background: Tinnitus sufferers commonly report concentration difficulties. Despite several previous studies investigating this, the underlying cause and the role of hearing status remains unclear. Purpose: To investigate whether there are any differences between normal hearing individuals with and without tinnitus in terms of working memory capacity, and whether working memory capacity correlates with high-frequency hearing thresholds. Research Design: Participants had their hearing thresholds measured (0.125-16 kHz) and performed a visual n-back test. All participants completed the Hospital Anxiety and Depression Scale, in addition tinnitus participants filled out the Tinnitus Questionnaire. Study Sample: Sixty-two individuals participated, 31 had tinnitus (tinnitus group) and 31 did not have tinnitus (control group). Groups were age- and sex matched, and all participants had normal hearing thresholds (20 dB HL or better at 0.125-8 kHz). Data Analysis: Friedman test of differences among repeated measures was conducted on the collected data of n-back performance, and Mann-Whitney U-test was used to compare groups. Age-corrected correlations were calculated for high-frequency hearing and each n-back condition. Results: We found no significant differences between the groups in terms of n-back task performances, except for the 2-back condition where the tinnitus group performed significantly better than the controls (p = 0.007). Furthermore, we found high-frequency hearing thresholds of the best ear (10-16 kHz) to correlate with performances at more demanding n-back conditions (p = 0.029 for 1-back and p = 0.015 for 2-back). Conclusion: This suggests that presence of tinnitus might not imply poorer working memory capacity and that deteriorated high-frequency hearing thresholds