Age standardization and time-of-day performance for the Oldenburg Sentence Test (OLSA): results from the population-based Gutenberg Health Study.

PURPOSE: The Oldenburg Sentence Test (OLSA) is a German matrix test designed to determine speech recognition thresholds (SRT). It is widely used for hearing-aids and cochlear implant fitting, but an age-adjusted standard is still lacking. In addition, knowing that the ability to concentrate is an important factor in OLSA performance, we hypothesized that OLSA performance would depend on the time of day it was administered. The aim of this study was to propose an age standardization for the OLSA and to determine its diurnal performance. METHODS: The Gutenberg Health Study is an ongoing population-based study and designed as a single-centre observational, prospective cohort study. Participants were interviewed about common otologic symptoms and tested with pure-tone audiometry and OLSA. Two groups-subjects with and without hearing loss-were established. The OLSA was performed in two runs. The SRT was evaluated for each participant. Results were characterized by age in 5-year cohorts, gender and speech recognition threshold (SRT). A time stamp with an hourly interval was also implemented. RESULTS: The mean OLSA SRT was - 6.9 ± 1.0 dB (group 1 male) and - 7.1 ± 0.8 dB (group 1 female) showing an inverse relationship with age in the whole cohort, whereas a linear increase was observed in those without hearing loss. OLSA-SRT values increased more in males than in females with increasing age. No statistical significance was found for the diurnal performance. CONCLUSIONS: A study with 2900 evaluable Oldenburg Sentence Tests is a novelty and representative for the population of Mainz and its surroundings. We postulate an age- and gender-standardized scale for the evaluation of the OLSA. In fact, with an intergroup standard deviation (of about 1.5 dB) compared to the age dependence of 0.7 dB/10 years, this age normalization should be considered as clinically relevant.

[The adaptive Freiburg monosyllabic test in noise : Development of a procedure and comparison of the results with the Oldenburg sentence test]. / Die adaptive Messung des Freiburger Einsilbertests im Störschall : Entwicklung einer Messmethode und Vergleich der Ergebnisse mit dem Oldenburger Satztest.

BACKGROUND: Whereas sentence tests are commonly performed using an adaptive procedure, this method has not yet been transferred to the Freiburg monosyllabic speech test, the most important word test. When using different procedures, a comparison of results between sentence and word tests is not possible. Therefore, an adaptive procedure which has proven itself in sentence tests was transferred to the Freiburg monosyllabic test in noise. The results of the new procedure were compared to the standard of sentence tests, i.e., the Oldenburg sentence test. METHODS: The adaptive Freiburg monosyllabic speech test and the Oldenburg sentence test were applied in 40 otologically normal subjects in a randomized order. Results were analyzed with respect to time requirements, possible gender differences, the influence of test order, and correlation of test results. RESULTS: The time required for the adaptive Freiburg monosyllabic speech test was significantly higher than for the Oldenburg sentence test. No significant impact of gender or test order could be shown. The mean signal-to-noise ratio for 50% speech discrimination of the Oldenburg sentence test was significantly smaller than for the adaptive Freiburg monosyllabic speech test. No correlation could be shown between the results of the two tests CONCLUSION: The Freiburg monosyllabic test can not only be used for quantifying discrimination loss in percentage terms, but also to measure the 50% speech recognition threshold with an adaptive algorithm. However, the procedure of the adaptive Freiburg monosyllabic test is more time consuming than that of the Oldenburg sentence test. Concerning a possible missing correlation between the results for 50% speech discrimination, further studies with hearing-impaired persons are needed.

Investigation of a matrix sentence test in noise: reproducibility and discrimination function in cochlear implant patients.

OBJECTIVE: The aim of this study was to describe common properties (reproducibility, discrimination function, and its steepness) of matrix tests used for cochlear implant (CI) users and to obtain data for the German-language version matrix test, the Oldenburg sentence test (OLSA), presented in noise. DESIGN: The speech reception thresholds (SRT) in noise were measured by means of an adaptive test procedure, and by measurement at various signal-to-noise ratios to determine the course of the entire discrimination function per subject. STUDY SAMPLE: The measurements were performed on 38 CI users fitted with a Cochlear(™) Freedom(®) or a Cochlear(™) Nucleus(®) 5 CI system. RESULTS: The test-retest reproducibility showed a significant dependence on the SRT in noise. For the better performers, the test-retest difference was found to be smaller, while for the poorer performers the difference increased. For the better performers, the slope of the discrimination function at SRT (s50) was comparable to that for individuals with normal hearing, while for the poorer performers the s50 tended to be significantly reduced. CONCLUSIONS: As the CI users differed significantly in their SRT and their s50, a unified discrimination function for CI users must not be used. Further tailoring of the procedure may be required, especially for poorer CI performers.

Effect of Contralateral Noise on Speech Intelligibility.

In patients with strong asymmetric hearing loss, standard clinical practice involves testing speech intelligibility in the ear with the higher hearing threshold by simultaneously presenting noise to the other ear. However, psychoacoustic and functional magnetic resonance imaging (fMRI) studies indicate that this approach may be problematic as contralateral noise has a disruptive effect on task processing. Furthermore, fMRI studies have revealed that the effect of contralateral noise on brain activity depends on the lateralization of task processing. The effect of contralateral noise is stronger when task-relevant stimuli are presented ipsilaterally to the hemisphere that is processing the task. In the present study, we tested the effect of four different levels of contralateral noise on speech intelligibility using the Oldenburg sentence test (OLSA). Cortical lateralization of speech processing was assessed upfront by using a visual speech test with fMRI. Contralateral OLSA noise of 65 or 80 dB SPL significantly reduced word intelligibility irrespective of which ear the speech was presented to. In participants with left-lateralized speech processing, 50 dB SPL contralateral OLSA noise led to a significant reduction in speech intelligibility when speech was presented to the left ear, i.e. when speech was presented ipsilaterally to the hemisphere that is mainly processing speech. Thus, contralateral noise, as used in standard clinical practice, not only prevents listeners from using the information in the better-hearing ear but may also have the unintended effect of hampering central processing of speech.

Measuring Speech Recognition With a Matrix Test Using Synthetic Speech.

Speech audiometry is an essential part of audiological diagnostics and clinical measurements. Development times of speech recognition tests are rather long, depending on the size of speech corpus and optimization necessity. The aim of this study was to examine whether this development effort could be reduced by using synthetic speech in speech audiometry, especially in a matrix test for speech recognition. For this purpose, the speech material of the German matrix test was replicated using a preselected commercial system to generate the synthetic speech files. In contrast to the conventional matrix test, no level adjustments or optimization tests were performed while producing the synthetic speech material. Evaluation measurements were conducted by presenting both versions of the German matrix test (with natural or synthetic speech), alternately and at three different signal-to-noise ratios, to 48 young, normal-hearing participants. Psychometric functions were fitted to the empirical data. Speech recognition thresholds were 0.5 dB signal-to-noise ratio higher (worse) for the synthetic speech, while slopes were equal for both speech types. Nevertheless, speech recognition scores were comparable with the literature and the threshold difference lay within the same range as recordings of two different natural speakers. Although no optimization was applied, the synthetic-speech signals led to equivalent recognition of the different test lists and word categories. The outcomes of this study indicate that the application of synthetic speech in speech recognition tests could considerably reduce the development costs and evaluation time. This offers the opportunity to increase the speech corpus for speech recognition tests with acceptable effort.