[Evaluation of the Freiburg monosyllabic speech test in background noise]

[The adaptive use of the Freiburg mono-syllabic speech test in noise with a few number of test-lists]

BACKGROUND

Considering the different calibration and masking of the noise, the adaptive Freiburg monosyllabic speech test in noise (aFBE-S) and the Oldenburg sentence test in noise (OLSA-S) were shown to be comparable with respect to the accuracy of both tests in a previous study. However, the time requirement of the aFBE-S was significantly greater than that of the OLSA-S due to the adaptive measurement method. The purpose of this study is to theoretically determine whether the aFBE-S can be used with fewer test lists, given the low scatter of results, and to compare the results with those of the OLSA-S.

METHODS

Using the results of 40 otologically healthy subjects who had already been tested in randomized order with the OLSA-S and aFBE-S, the mean difference of the 95 % confidence interval (95 % CI) of the signal-to-noise ratio for 50% speech understanding (S/N50) of the aFBE-S was calculated for three, four, and five test lists instead of 7.5. In addition, the time required for the reduced number of test lists was determined and the results were examined in comparison with those of the OLSA-S.

RESULTS

In each case, no significant difference between the difference mean of the 95 %-CI of the S/N50 of the original aFBE-S, the aFBE-S shortened to 3, 4, or 5 test lists and the OLSA-S could be found. The time required for the aFBE-S with a reduced number of test lists was significantly less than for the OLSA-S in each case.

CONCLUSION

The aFBE-S is not inferior with a reduced number of test lists in comparison to the OLSA-S. This would allow to use the shortened aFBE-S theoretically.

[Correlation between the APHAB questionnaire and the Freiburg monosyllabic test without + with noise]

BACKGROUND

Questionnaires, e. g. the APHAB, and speech-audiometry are the most used elements in measuring the success of hearing aid fitting (HAF). This study investigates the correlations between the results of the Freiburg monosyllabic word test without and with noise (FBE, FBE-S) and the results of the APHAB before and after HAF.

METHODS

Data of the FBE, the FBE-S, and the APHAB, generated within HAF of 156 subjects were analyzed. After exclusion of a normal distribution of the data, Spearman's correlation and Cohen's effect size were determined.

RESULTS

73 (46.8 %) of the 156 subjects were females, and 83 (53.2 %) males. No significant correlation could be found between the EC-, the RV-, and the cumulative ECBNRV-subscale and the benefit of HAF in the FBE and FBE-S (EC: ease of communication, BN: background noise, RV: reverberation). Most of the remaining coefficients of correlation had a weak positive effect size. A middle positive effect size could only be demonstrated for 6 combinations, for the EC-subscale mostly.

CONCLUSION

The not strong effect sizes could assume that the results in speech-audiometry and the APHAB are not independent and complementing each other as parameters of hearing loss and benefit in HAF. The effect size could be explained by individually different possibilities for the compensation of hearing loss.

Long-Term Safety and Quality of Life after Vibroplasty in Sensorineural Hearing Loss: Short/Long Incus Process Coupler

OBJECTIVE

The study shows the long-term effectiveness, safety, and quality of life after Vibrant Soundbridge (VSB) implantation in sensorineural hearing loss (SNHL) using the short process coupler (SP) or the long process coupler (LP).

METHODS

This retrospective study evaluated 77 VSB cases. Follow-up (F/U) time-dependent objective measurements (audiological outcomes), subjective data collection (quality-of-life questionnaire), and safety measures are presented.

RESULTS

Sixty-two ears were included in the analysis with up to 116 months of postsurgical F/U data (mean 32.15 ± 37.97 months LP and SP coupler). Fifty-three ears (13 bilateral cases) received the LP coupler and 9 subjects the SP coupler. The post-operative bone conduction thresholds remained stable and, in both groups, <10 dB. The benefit in word recognition scores measured at 65 dB SPL and 80 dB SPL showed no significant difference between the couplers (p = 0.559 and p = 0.088, respectively). The functional gain was not significantly different (p > 0.05) with a mean of 20.91 ± 9.77 and 17.19 ± 5.75 for LP and SP coupler, respectively. The utility score deciphered from the Assessment of Quality-of-life Questionnaire-8 dimensions revealed a mean score of 0.75 ± 0.16 which is not significantly different to the age- and sex-matched healthy control group with 0.81 ± 0.02 (p = 0.3547).

CONCLUSION

The Incus Vibroplasty utilizing both couplers is a safe and effective method to treat mild-to-severe SNHL. Both fixation methods of the floating mass transducer exhibit good clinical and audiological outcomes with high patient quality of life. The SP coupling method can be a good alternative when the long process is anatomically inaccessible, or the approach is limited due to anatomical reasons.

Die Verständlichkeitskurve für den Freiburger Einsilbertest im Störschall mit einem Signal-Rausch-Abstand (SNR) von 5 dB

Hintergrund

Der Freiburger Einsilbertest (FBE) ist seit Langem einer der wesentlichen deutschen Sprachhörtests. Seit einiger Zeit wird er auch zur Messung der Hörverbesserung im Rahmen einer Hörgeräteversorgung im Störschall verwendet (FBE-S). Mit dieser Studie soll eine Verständlichkeitskurve für den Freiburger Einsilbertest im Störschall mit fixem Signal-Störschall-Verhältnis von 5 dB bei verschiedenen Schalldruckpegeln bestimmt werden.

Methode

Im Herbst 2018 wurden 60 normalhörende, muttersprachlich Deutsch sprechende Probanden im Alter zwischen 18 und 31 Jahren in der Klinik für HNO-Heilkunde des Bundeswehrkrankenhauses in Hamburg untersucht. Das Sprachverstehen wurde mit einer Testliste des FBE mit einem Schalldruckpegel von 15 bis 90 dB und einem 5 dB niedrigeren Störschall in 5‑dB-Schritten gemessen. Anschließend wurden von den Verständlichkeitsquoten die Mittelwerte gebildet und die 95%-Konfidenzintervalle (95%-KI) bestimmt.

Ergebnisse

Es nahmen 29 weibliche und 31 männliche Probanden an der Untersuchung teil. Das mittlere Alter aller Probanden betrug 24,32 Jahre (±3,39 Jahre). In der Varianzanalyse für fixe Effekte mit der Verständlichkeit als abhängiger Variablen zeigte sich ein hochsignifikanter Zusammenhang zwischen den Schalldruckpegeln des Sprach- und Störschalls auf der einen Seite und der Verständlichkeit auf der anderen Seite (p < 0,001). Die gemittelten Verständlichkeitsquoten und zugehörigen 95%-KI sowie die Häufigkeitsverteilungen wurden tabellarisch und grafisch dargestellt.

Schlussfolgerung

Die Verständlichkeitskurve des FBE‑S ist im Vergleich zur Normkurve des FBE nach rechts verschoben. Die gemittelte Kurve des FBE‑S erreicht bei einem Schalldruckpegel von 70 dB und einem Störschalldruckpegel von 65 dB den Sättigungsbereich von 90 % Verständlichkeit (zum Vergleich: Der Sättigungspunkt von 100 % Verständlichkeit liegt beim FBE ohne Störschall bei 55 dB). Durch die hier vorgestellte Verständlichkeitskurve lassen sich individuelle Messergebnisse ohne und mit Hörgeräten besser interpretieren. Künftig sollte der Hörgewinn für Hörgeräte möglicherweise bei niedrigeren Schalldruckpegeln erfolgen als heute.

[The adaptive Freiburg monosyllabic test in noise : Development of a procedure and comparison of the results with the Oldenburg sentence test]

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.

[Speech audiometry and data logging in CI patients : Implications for adequate test levels. German version]

BACKGROUND

As part of postoperative cochlear implant (CI) diagnostics, speech comprehension tests are performed to monitor audiological outcome. In recent years, a trend toward improved suprathreshold speech intelligibility in quiet and an extension of intelligibility to softer sounds has been observed. Parallel to audiometric data, analysis of the patients' acoustic environment can take place by means of data logging in modern CI systems.

OBJECTIVES

Which test levels reflect the individual listening environment in a relevant manner and how can these be reflected in a clinical audiometric setting?

PATIENTS AND METHODS

In a retrospective analysis, data logs of 263 adult CI patients were evaluated for sound level and the listening situation (quiet, speech in quiet, noise, speech in noise, music, and wind). Additionally, monosyllabic word comprehension in quiet was analyzed in experienced CI users at presentation levels of 40-80 dB.

RESULTS

For the sound level in the acoustic environment of postlingually deafened adult CI users, data logging shows a maximum occurrence of speech signals in the range 50-59 dB. This demonstrates the relevance of everyday speech comprehension at levels below 60 dB.

CONCLUSIONS

Individual optimization of speech intelligibility with a CI speech processor should not be performed in the range of 65-70 dB only, but also at lower levels. Measurements at 50 dB currently seem to be a useful addition.

Current audiological diagnostics

Today’s audiological functional diagnostics is based on a variety of hearing tests, whose large number takes account of the variety of malfunctions of a complex sensory organ system and the necessity to examine it in a differentiated manner and at any age of life. The objective is to identify nature and origin of the hearing loss and to quantify its extent as far as necessary to dispose of the information needed to initiate the adequate medical (conservative or operational) treatment or the provision with technical hearing aids or prostheses. Moreover, audiometry provides the basis for the assessment of impairment and handicap as well as for the calculation of the degree of disability. In the present overview, the current state of the method inventory available for practical use is described, starting from basic diagnostics over to complex special techniques. The presentation is systematically grouped in subjective procedures, based on psychoacoustic exploration, and objective methods, based on physical measurements: preliminary hearing tests, pure tone threshold, suprathreshold processing of sound intensity, directional hearing, speech understanding in quiet and in noise, dichotic hearing, tympanogram, acoustic reflex, otoacoustic emissions and auditory evoked potentials. Apart from a few still existing gaps, this method inventory covers the whole spectrum of all clinically relevant functional deficits of the auditory system.

[The Freiburg speech intelligibility test : A pillar of speech audiometry in German-speaking countries]

The Freiburg speech intelligibility test according to DIN 45621 was introduced around 60 years ago. For decades, and still today, the Freiburg test has been a standard whose relevance extends far beyond pure audiometry. It is used primarily to determine the speech perception threshold (based on two-digit numbers) and the ability to discriminate speech at suprathreshold presentation levels (based on monosyllabic nouns). Moreover, it is a measure of the degree of disability, the requirement for and success of technical hearing aids (auxiliaries directives), and the compensation for disability and handicap (Königstein recommendation). In differential audiological diagnostics, the Freiburg test contributes to the distinction between low- and high-frequency hearing loss, as well as to identification of conductive, sensory, neural, and central disorders. Currently, the phonemic and perceptual balance of the monosyllabic test lists is subject to critical discussions. Obvious deficiencies exist for testing speech recognition in noise. In this respect, alternatives such as sentence or rhyme tests in closed-answer inventories are discussed.

[Evaluation of hearing aid rehabilitation using the Freiburg Monosyllabic Test]

The benefit of hearing aids is not always directly subjectively perceivable. Therefore, objective and quantifiable speech audiometric measurements are required. Beside acoustic gain measurements and structured interviews, speech audiometry in quiet and in noise is one of the three pillars of hearing aid evaluation.The Freiburg monosyllabic test has been used for decades for hearing aid prescription and evaluation in German speaking countries. Relative and absolute targets can be individually defined for the rehabilitation of speech perception by hearing aids as assessed by the Freiburg monosyllabic test in quiet and at conversational levels.The general applicability of speech audiometric measurements in noise is limited. Alternative ("modern") methods and the definitions of noise situations relevant to everyday life have been discussed for years. However, the introduction of these methods into everyday use has proven difficult. On one hand, there is comparatively little practical experience; on the other, it has not yet been demonstrated what additional benefits these more complicated measurements might have for standard hearing aid evaluations and hearing aid users.

[Use of Freiburg monosyllabic test words in the contemporary German language : Currentness of the test words]

The Freiburg monosyllabic test has a word inventory based on the word frequency in written sources from the 19th century, the distribution of which is not even between the test lists. The median distributions of word frequency ranking in contemporary language of nine test lists deviate significantly from the overall median of all 400 monosyllables. Lists 1, 6, 9, 10, and 17 include significantly more very rarely used words; lists 2, 3, 5, and 15, include significantly more very frequently used words. Compared with the word frequency in the contemporary spoken German language, about 45 % of the test words are practically no longer used. Due to this high proportion of extremely rarely or no longer used words, the word inventory is no longer representative of the contemporary German language-neither for the written, nor for the spoken language. Highly educated persons with a large vocabulary are thereby favored. The reference values for normal-hearing persons should therefore be reevaluated.

[Evaluation of the perceptual equivalence of test lists in the Freiburg monosyllabic speech test]

BACKGROUND

In the past, the perceptual balance of test lists for the Freiburg monosyllabic speech test (FBE) was frequently evaluated without producing consistent results. Until now, the studies used very diverse methods and did not accurately follow the standardized specifications. In this study, therefore, the perceptual equivalence of test lists was verified with a large group of participants according to the standard ISO EN 8253-3.

METHODS

A total of 160  suitable otologically normal subjects were recruited at two institutions, each of whom listened to all test lists of the FBE using predefined measurement conditions. The subjects were divided in three groups depending on the transducer used for test list presentation (headphones "HDA 200" and "TDH 39", as well as free-field loudspeaker, "FF"). Lists that deviated were identified using the approaches specified in the standard.

RESULTS

The reference curve for FBE was not met by any group. While the "HDA 200" group indicated 4.6 dB lower thresholds, results for the "TDH 39" and "FF" groups showed 1.2 and 2.5 dB higher thresholds, respectively. For an average speech recognition score of 44.3 %, test lists 5, 11, 12, and 15 lay outside the calculated tolerance range of 4.5 to -4.4 percent points. The same lists also deviated when calculating discrimination functions and therefore do not fulfill the criteria for perceptual equivalence.

DISCUSSION

In the future, lists identified as deviating from the norm should not be used. The results of this study only partly agree with results from former studies.

[The age effect in evaluation of hearing aid benefits by speech audiometry]

BACKGROUND AND AIM

Hearing loss is one of the most common disabilities in the elderly. The aim of this study was to investigate the relationship between pure-tone hearing loss and maximum monosyllabic perception and speech perception with hearing aids. The focus of the investigation was elderly patients.

MATERIALS AND METHODS

In this prospective study, 188 patients with sensorineural hearing loss were included. The pure-tone audiogram (4FPTA), the Freiburg speech intelligibility test with headphones and the word recognition score with hearing aids at 65 dB SPL were measured and evaluated.

RESULTS

An increasing age was associated with higher discrepancy between the maximum speech perception and speech understanding with hearing aids. The mean difference between maximum monosyllabic perception and speech perception with hearing aids is about 20% in the elderly population.

CONCLUSION

The intended goal of hearing aid prescription, the match between maximum monosyllabic perception and word recognition score with hearing aids within 5 to 10%, is not achieved in the elderly population.

[Influence of hearing aids on monosyllabic test score and subjective everyday hearing]

BACKGROUND

Pure tone and speech audiometry are essential methods for examining the indication for hearing aids, as well as for hearing aid evaluation. Additionally, the subjective benefit of hearing aids has to be evaluated with appropriate questionnaires. The aim of the present study was to investigate the correlation between speech audiometry data and the results of a simple and user-friendly questionnaire, as well as to provide normative data for subjective benefit.

MATERIALS AND METHODS

Data from 136 hearing aid users with bilateral sensorineural hearing loss were analyzed retrospectively. Pure tone thresholds and Freiburg monosyllabic speech perception in the binaural situation were measured at 65 dB in quiet and in noise (signal-to-noise ratio, SNR = +5 dB), with and without hearing aids. Additionally, subjective hearing in everyday life was recorded using the 12-item Oldenburg Inventory.

RESULTS

Improvement of speech perception with hearing aids for the Freiburg monosyllabic test in quiet was 32.0 percentage points on average; in noise, there was an average improvement of 16.4 percentage points. There was a strong correlation between the results of pure tone and speech audiometry. With hearing aids, patients scored their everyday hearing using the Oldenburg Inventory on average 1.4 scale points better than without hearing aids. Results of the Oldenburg Inventory correlate with both pure tone and speech audiometry.

CONCLUSION

Hearing aid evaluation should include both speech audiometry and systematic measurement of the subjective benefit using a suitable questionnaire. In combination, the Freiburg monosyllabic test and the Oldenburg Inventory allow for quick and comprehensive evaluation.

[Detection of hearing loss in dementia patients : pilot study and literature survey]

There is a higher incidence of dementia among people with hearing loss, although the complex interrelation is not yet understood. The potential influence of hearing rehabilitation is also unclear. A previously published retrospective study on this topic throws doubt on the ability of dementia patients to accomplish audiometric tests. Therefore, we conducted a pilot study to analyse the feasibility of applying conventional speech and pure tone audiometry in patients with dementia. In contrast to previously published data, we were able to achieve reproducible results in almost all patients. The difficulty associated with audiometric testing in dementia patients does thus not seem to lie in the application of pure tone and speech audiometry. On the basis of evidence indicating the importance of central hearing loss in the elderly, these tests alone do not appear sufficient. It is of greater interest to ascertain whether central hearing loss is relevant in patients suffering from dementia and whether corresponding audiometric tests are feasible.

[Implementation of the new quality assurance agreement for the fitting of hearing aids in daily practice. Part 2: New diagnostic aspects of speech audiometry]

Upon review of the statutory health insurance reimbursement guidelines, a specific quality assurance questionnaire concerned with the provision of hearing aids was introduced that assesses elements of patient satisfaction within Germany's public healthcare system. APHAB questionnaire-based patient evaluation of the benefit of hearing aids represents the third pillar of audiological diagnostics, alongside classical pure-tone and speech audiometry. Another new aspect of the national guidelines is inclusion of free-field measurements in noise with and without hearing aids. Part 2 of this review describes new diagnostic aspects of speech audiometry. In addition to adaptive speech audiometry, a proposed method for applying the gold standard of speech audiometry - the Freiburg monosyllabic speech test - in noise is described. Finally, the quality assurance questionnaire will be explained as an appendix to template 15 of the regulations governing hearing aids.

Results in using the Freiburger monosyllabic speech test in noise without and with hearing aids

The Freiburger Speech Test (FST) has been the gold standard in speech testing by word recognition score in Germany for many years. Recently, it has been demonstrated that for an amount of 104 test-persons there is no significant deviation within the lists. The objective of this study was to determine the percentiles of the distinct measuring situations in quiet and with noise (e.g. applied in hearing aid fitting) and the average benefit using hearing aids. In this prospective study, 623 patients with SNHL and equipped with hearing aids for at least 3 months have been investigated by means of the Freiburger monosyllabic test (FBE) without and with hearing aids and in quiet or with noise (CCITT noise, 65/60 dB signal-noise ratio) in free field conditions at 65 dB to determine the ratio of intelligibility. To investigate the different diagnostic conditions a linear mixed model was applied. The dependent binary variable corresponds to the number of understood syllables. The average age of all subjects was about 72.6 years. The average rate of understanding in the FBE without hearing aids and in quiet was 38.5 %, with hearing aids and in quiet 67.7 %, without hearing aids and with noise 22.4 %, and with hearing aids and with noise 39.8 %. All results were presented with the depending confidence intervals. The extent of hearing loss and the quality of hearing aid fitting can be successfully measured using the FST in quiet and with background noise (CCITT noise). In quiet, an average hearing improving gain of 29.2 % points and with noise a gain of 17.4 % points could be estimated with a successful hearing aid fitting.