Shortened neural conduction time in young adults with tinnitus as revealed by chirp-evoked auditory brainstem response

Tinnitus is generally considered to be caused by neuroplastic changes in the central nervous system, triggered by a loss of input from the damaged peripheral system; however, conflicting results on auditory brainstem responses (ABRs) to clicks have been reported previously in humans with tinnitus. This study aimed to compare the effect of tinnitus on ABRs to chirps with those to clicks in normal-hearing young adults with tinnitus. The results showed that the tinnitus group had no significantly poorer hearing thresholds (0.25-16 kHz), click-evoked otoacoustic emissions (1-16 kHz), and speech perception in noise (SPIN) than the control group. Although chirps evoked significantly larger wave I and V amplitudes than clicks, people with tinnitus had no significantly smaller wave I amplitudes for either stimulus. Nevertheless, adults with tinnitus exhibited significantly smaller interpeak interval (IPI) between waves I and V for chirps (IPI-chirp) but not for clicks. In addition, the IPI-chirp correlated significantly with the SPIN for individuals with tinnitus when the signal-to-noise ratio was low. The present results suggest that the chirp-evoked ABR may be a valuable clinical tool for objectively assessing the SPIN in individuals with tinnitus. Further studies should be conducted to investigate possible etiologies of tinnitus.

The German hearing in noise test with a female talker: development and comparison with German male speech test

PURPOSE

The aim of the study was to develop the German Hearing in Noise Test (HINT) with female speaker by fulfilling the recommendations by International Collegium of Rehabilitative Audiology (ICRA) for using a female speaker to create new multilingual speech tests and to determine norms and to compare these norms with German male speech tests-the male speakers HINT and the Oldenburg Sentence Test (OLSA).

METHODS

The HINT with a female speaker consists of the same speech material as the male speaking HINT. After recording the speech material, 10 normal hearing subjects were included to determine the performance-intensity function (PI function). 24 subjects were part of the measurements to determine the norms and compare them with the norms of male HINT and OLSA. Comparably, adaptive, open-set methods under headphones (HINT) and sound field (OLSA) were used.

RESULTS

Acoustic phonetic analysis demonstrated significant difference in mean fundamental frequency, its range and mean speaking rate between both HINT speakers. The calculated norms by three of the tested four conditions of the HINT with a female speaker are not significantly different from the norms with a male speaker. No significant effect of the speaker's gender of the first HINT measurement and no significant correlation between the threshold results of the HINT and the OLSA were determined.

CONCLUSIONS

The Norms for German HINT with a female speaker are comparable to the norms of the HINT with a male speaker. The speech intelligibility score of the HINT does not depend on the speakers' gender despite significant difference of acoustic-phonetic parameters between the female and male HINT speaker's voice. Instead, the speech intelligibility rating must be seen as a function of the used speech material.

The Swedish hearing in noise test for children, HINT-C

OBJECTIVE

The aim of this study was to develop and evaluate a Swedish version of the Hearing In Noise Test for Children (HINT-C).

DESIGN

In the first part, the Swedish HINT lists for adults was evaluated by children at three signal to noise ratios (SNRs), -4, -1 and +2 dB. Lists including sentences not reaching 50% recognition at +2 dB SNR were excluded and the rest constituted the HINT-C. In the second part, HINT-C was evaluated in children and adults using an adaptive procedure to determine the SNR for 50% correctly repeated sentences. Study Sample In the first part, 112 children aged 6-11 years participated while another 28 children and 9 adults participated in the second part.

RESULTS

Eight out of 24 tested adult HINT lists did not reach the inclusion criteria. The remaining 16 lists formed the Swedish HINT-C which was evaluated in children 6-11 years old. A regression analysis showed that the predicted SNR threshold (dB) was 0.495-0.365*age (years + months/12) and the children reached the mean adult score at an age of 10.5 years.

CONCLUSIONS

A Swedish version of HINT-C was developed and evaluated in children six years and older.

A convergent validity study: Listening in Spatialized Noise-Sentences (LiSN-S) test and the Hearing in Noise Test (HINT)

OBJECTIVES

The primary purpose of this study was to compare Listening in Spatialized Noise - Sentence (LiSN-S) test and the Hearing in Noise Test (HINT) thresholds in order to determine if the two tests measure the same construct (convergent validity). The secondary purpose was to determine performance differences between the two test protocols. The third purpose was to determine the relationships between quiet measures (pure-tone average [PTA] and HINT Quiet thresholds) vs. speech-in-noise performances.

DESIGN

Statistical analyses included descriptive statistics, Spearman rho statistic, repeated measures analysis of variance (ANOVA) and linear mixed model analyses. Study sample: Fifty-six young adults with normal PTAs (≤15 dB HL for 0.5-4.0 kHz) participated in this study.

RESULTS

No statistically significant relationships were found between LiSN-S and HINT measures (poor convergent validity). However, statistically significant relationships were found between the quiet measures (HINT Quiet thresholds and average PTA_{(0.5-4.0 kHz)}) vs. the LiSN-S (same and different voices) ±90° performances.

CONCLUSION

LiSN-S performances in two-talker babble cannot be generalized to the ability to recognise HINT sentences in steady-state speech-shaped noise, and vice versa. The results imply that LiSN-S ± 90° thresholds were influenced by hearing sensitivity or by supra-threshold distortions that co-vary with hearing sensitivity.