Category Archives: Ear Hear

The Gap Detection Test: Can It Be Used to Diagnose Tinnitus?

Ear Hear. 2015 Mar 27;

Authors: Boyen K, Başkent D, van Dijk P

Abstract
OBJECTIVES: Animals with induced tinnitus showed difficulties in detecting silent gaps in sounds, suggesting that the tinnitus percept may be filling the gap. The main purpose of this study was to evaluate the applicability of this approach to detect tinnitus in human patients. The authors first hypothesized that gap detection would be impaired in patients with tinnitus, and second, that gap detection would be more impaired at frequencies close to the tinnitus frequency of the patient.
DESIGN: Twenty-two adults with bilateral tinnitus, 20 age-matched and hearing loss-matched subjects without tinnitus, and 10 young normal-hearing subjects participated in the study. To determine the characteristics of the tinnitus, subjects matched an external sound to their perceived tinnitus in pitch and loudness. To determine the minimum detectable gap, the gap threshold, an adaptive psychoacoustic test was performed three times by each subject. In this gap detection test, four different stimuli, with various frequencies and bandwidths, were presented at three intensity levels each.
RESULTS: Similar to previous reports of gap detection, increasing sensation level yielded shorter gap thresholds for all stimuli in all groups. Interestingly, the tinnitus group did not display elevated gap thresholds in any of the four stimuli. Moreover, visual inspection of the data revealed no relation between gap detection performance and perceived tinnitus pitch.
CONCLUSIONS: These findings show that tinnitus in humans has no effect on the ability to detect gaps in auditory stimuli. Thus, the testing procedure in its present form is not suitable for clinical detection of tinnitus in humans.

PMID: 25822647 [PubMed – as supplied by publisher]

Continue reading →

A Retrospective Multicenter Study Comparing Speech Perception Outcomes for Bilateral Implantation and Bimodal Rehabilitation.

Ear Hear. 2015 Feb 18;

Authors: Blamey PJ, Maat B, Başkent D, Mawman D, Burke E, Dillier N, Beynon A, Kleine-Punte A, Govaerts PJ, Skarzynski PH, Huber AM, Sterkers-Artières F, Van de Heyning P, O’Leary S, Fraysse B, Green K, Sterkers O, Venail F, Skarzynski H, Vincent C, Truy E, Dowell R, Bergeron F, Lazard DS

Abstract
OBJECTIVES:: To compare speech perception outcomes between bilateral implantation (cochlear implants [CIs]) and bimodal rehabilitation (one CI on one side plus one hearing aid [HA] on the other side) and to explore the clinical factors that may cause asymmetric performances in speech intelligibility between the two ears in case of bilateral implantation.
DESIGN:: Retrospective data from 2247 patients implanted since 2003 in 15 international centers were collected. Intelligibility scores, measured in quiet and in noise, were converted into percentile ranks to remove differences between centers. The influence of the listening mode among three independent groups, one CI alone (n = 1572), bimodal listening (CI/HA, n = 589), and bilateral CIs (CI/CI, n = 86), was compared in an analysis taking into account the influence of other factors such as duration of profound hearing loss, age, etiology, and duration of CI experience. No within-subject comparison (i.e., monitoring outcome modifications in CI/HA subjects becoming CI/CI) was possible from this dataset. Further analyses were conducted on the CI/CI subgroup to investigate a number of factors, such as implantation side, duration of hearing loss, amount of residual hearing, and use of HAs that may explain asymmetric performances of this subgroup.
RESULTS:: Intelligibility ranked scores in quiet and in noise were significantly greater with both CI/CI and CI/HA than with a CI-alone group, and improvement with CI/CI (+11% and +16% in quiet and in noise, respectively) was significantly better than with CI/HA (+6% and +9% in quiet and in noise, respectively). From the CI/HA group, only subjects with ranked preoperative aided speech scores >60% performed as well as CI/CI participants. Furthermore, CI/CI subjects displayed significantly lower preoperative aided speech scores on average compared with that displayed by CI/HA subjects. Routine clinical data available from the present database did not explain the asymmetrical results of bilateral implantation.
CONCLUSIONS:: This retrospective study, based on basic speech audiometry (no lateralization cues), indicates that, on average, a second CI is likely to provide slightly better postoperative speech outcome than an additional HA for people with very low preoperative performance. These results may be taken into consideration to refine surgical indications for CIs.

PMID: 25695925 [PubMed – as supplied by publisher]

Continue reading →