Exploring auditory temporal resolution and dichotic listening skills among individuals with type 2 diabetes mellitus.

The study aimed to explore the auditory temporal resolution and dichotic listening skills in patients with type 2 diabetes mellitus (T2DM) and identify associated health-related factors. Using a cross-sectional design, 87 adults with T2DM and 48 non-diabetic controls, all with normal hearing, participated. The two central auditory processing (CAP) skills were assessed through the Gaps-In-Noise (GIN) and Dichotic-Digits Listening (DDL) tests. T2DM participants underwent blood tests to measure various health-related factors. In the GIN test, the shortest gap threshold (GapTh) obtained across both ears was significantly higher in the diabetic group (9.1 ± 2.4 ms) compared to the non-diabetic group (7.5 ± 1.5 ms), and the score of correctly identified gaps (GapSc) in the diabetic group (45±11 %) was significantly lower than GapSc in the non-diabetic group (52±9 %), p < 0.001. In the DDL test, the free-recall score (73.8 ± 18.5 %) across both ears and the right-ear advantage (-1.3 ± 20.6 %) in the diabetic group were significantly lower than the free-recall score (85.8 ± 11.9 %) and right-ear advantage (6.9 ± 11.9 %) in the non-diabetic group, p < 0.005. Furthermore, the duration of diabetes, eGFR level, retinopathy, carotid plaque, fasting blood glucose level, and HDL-C (good cholesterol) level were factors significantly associated with performances in the GIN and/or DDL tests for T2DM participants. In conclusion, individuals with T2DM are at risk of reduced auditory processing skills in temporal resolution and dichotic listening, impacting their speech understanding. Six health-related factors were identified as significantly associated with CAP skills in T2DM patients.

Influence of Speech Recognition Ability on Acceptable Noise Level for Mandarin (Chinese) Speakers with Normal Hearing.

INTRODUCTION: Noise can induce hearing loss and reduce speech understanding. The Acceptable Noise Level (ANL) test has been widely used in audiology. However, strategies used by listeners to determine ANLs are unclear. The current study evaluated the role of speech recognition in selecting ANL and how well ANL could predict speech understanding in a noisy situation. METHODS: Forty-five Mandarin speakers with normal hearing were tested in both ears. ANL is defined as Most Comfortable Level (MCL) minus Background Noise Level (BNL). To obtain ANL monaurally with an earphone, the study measured participants' MCL to hear a Mandarin story in quiet and the maximum BNL to tolerate while following the story. Then, based on the participant's ANL, speech recognition in noise was examined using a set of phonemic-balanced Mandarin words. The signal-to-noise ratio (SNR) was adjusted to ANL, ANL - 10 dB ("degraded noise condition"), and ANL + 10 dB ("improved noise condition"). RESULTS: The mean ANLs were 2.4 dB and 2.6 dB for the left and right ears, respectively. The mean speech recognition with SNR adjusted to ANL was relatively high for both ears (81-83% correct). Even for those ear samples with very low ANL (<0 dB), speech performance obtained at SNR = ANL was still high. The mean speech recognition obtained at SNR = ANL was 5 percentage points lower than the mean speech recognition at the improved noise condition and 14 percentage points higher than the mean speech recognition at the degraded noise condition. Speech recognition obtained at SNR = ANL and ANL - 10 dB correlated significantly with ANL. CONCLUSION: Speech recognition in noise appears to play an important role for listeners with normal hearing in deciding their ANLs. Additionally, ANL can predict speech performance (r-squared = 53-61%) in the degraded noise condition.

Curcumin activates autophagy and attenuates high glucose-induced apoptosis in HUVECs through the ROS/NF-κB signaling pathway.

Curcumin (CUR) is well known for its anti-inflammatory and antioxidant effects. However, the endothelial protective effect of CUR in diabetes and the underlying signaling pathway remains unclear. The goal of the current study was to provide evidence regarding the protective mechanism of CUR against the high glucose (HG)-induced damage to human umbilical vein endothelial cells (HUVECs). HG-induced HUVECs injury model was used to evaluate the protective effect and the underlying mechanism of CUR against endothelial injury. The cell viability was determined by the MTT method. The cell reactive oxygen species (ROS) were determined by using flow cytometry. The protein expression levels of Bcl-2, Bax, LC3-II/I, Beclin-1, p62, cleaved caspase-3, IκBα and NF-κB were measured by the western blotting. Results showed that CUR significantly decreased the cell apoptosis, the ROS generation and the inflammatory cytokine NF-κB activity in the HG-induced HUVECs versus the control, P<0.05. In addition, CUR significantly increased the expressions of LC3-II/I, Beclin-1, IκBα and Bax/Bcl-2 in the HG-induced HUVECs versus the control, P<0.05. Furthermore, the addition of autophagy inhibitor 3-MA impaired the autophagy, exacerbated the apoptotic death and increased the ROS and NF-κB levels in HUVECs under the high glucose condition, P<0.05. In brief, autophagy served a protective role in the HG-induced apoptosis in HUVECs and CUR alleviated apoptosis by promoting autophagy and inhibiting the ROS/NF-κB signaling pathway.

Dichotic listening using Mandarin CV-words of six plosives and vowel /a/.

OBJECTIVE: Available data on dichotic listening using tonal Chinese words have been limited, and conflicting results on a right-ear advantage (REA) have been reported. The current study developed a set of Mandarin CV-words based on the Bergen dichotic listening paradigm. DESIGN: The test materials consisted of two sets of stimuli. The English set, derived from the iDichotic application, consisted of six nonsense syllables with plosives conjugated to /a/. The Mandarin set had these 6 CV-syllables spoken as real words according to the Mandarin phonology. Study sample: Forty young, native Mandarin speakers were tested dichotically with both sets of test materials. Twenty participants were right-handed, and the other twenty were left-handed. Fourteen participants were randomly selected to repeat the test with the Mandarin set. RESULTS: The mean difference of correct recognition responses between two ears indicated a REA with both sets of stimuli for the right-handers, but not for left-handers. For the right-handers, performance with the Mandarin set was significantly better than performance with the English set. Dichotic listening with the Mandarin set had strong correlation between two time points, r = 0.8. CONCLUSIONS: Performance using the Mandarin set is reliable in dichotic listening; a REA is observed for the right-handers.

Factors affecting the Mandarin dichotic digits test.

Objective: Data with regard to the Mandarin dichotic digits test (DDT) are limited, with conflicting results reported between the Mandarin and English DDTs. The current study examined factors that might affect the performance in the Mandarin DDT. Design: The digits were arranged in 3 sets of 20 dichotic pairs; each set comprised 2, 3 or 4 digits in a pair. Study sample: Forty-one young, native Mandarin speakers with normal hearing were tested; 30 of them were right-handed and 11 left-handed. Six participants repeated the test. Results: The prevalence of ceiling effect in recognition score decreased systematically as the digit-pair length increased. At digit sets of 3-pair and 4-pair, the right-handed group showed a significant higher recognition score at right ear than left ear, while the left-handed group reversed the performance. The score difference between ears is significantly different between the right- and left-handed groups. The retest of the Mandarin DDT was reliable. Conclusions: For the right-handed group, a right-ear advantage can exist in the Mandarin DDT at a longer digit-pair length, similar to what was reported in the English DDT. Moreover, for the left-handed group, the attended right hemisphere in processing the tonal digits can result in a left-ear advantage.

Development of the Mandarin speech banana.

Purpose: For Indo-European languages, "speech banana" is widely used to verify the benefits of hearing aids and cochlear implants. As a standardised "Mandarin speech banana" is not available, clinicians in China typically use a non-Mandarin speech banana. However, as Chinese is logographic and tonal, using a non-Mandarin speech banana is inappropriate. This paper was designed to develop the Mandarin speech banana according to the Mandarin phonetic properties. Method: In the first experiment, 14 participants read aloud the standard Mandarin initials and finals. For each pronounced sound, its formants were measured. The boundary of all formants formed the formant graph (intensity versus frequency). In the second experiment, 20 participants listened to a list of pre-recorded initials and finals that had been filtered with different bandwidths. The minimum bandwidth to recognise a target sound defined its location on the formant graph. Result: The Mandarin speech banana was generated with recognisable initials and finals on the formant graph. Tone affected the shape of the formant graph, especially at low frequencies. Conclusion: Clinicians can use the new M andarin speech banana to counsel patients about what sounds are inaudible to them. Speech training can be implemented based on the unheard sounds in the speech banana.

Central conduction time in auditory brainstem response and ear advantage in dichotic listening across menstrual cycle.

The ovarian hormones fluctuate during the menstrual cycle in women. Such fluctuation of sex hormones, in particular estrogen, is believed to affect the central conduction time in auditory function as well as the language lateralization in cognitive function. However, findings are inconsistent. The underlying mechanisms are also unclear. This paper examined if there was any relation between the central conduction time and the language lateralization at different times during the menstrual cycle. Twenty young women with normal menstrual cycle were tested four times (5 to 7 days apart) across the menstrual cycle. The test battery included the electrophysiological measurement of auditory evoked response in brainstem and the speech performance in dichotic listening with monosyllables as stimulus pairs. The dichotic listening task was conducted under the non-forced, forced-right and forced-left attention. The central conduction time was defined by the time elapsed between two auditory elicited responses along the auditory pathway. The language lateralization in dichotic listening was expressed in ear advantage, which was the right-ear score minus the left-ear score. The results showed that the effects of test time were significant on both the central conduction time and the ear advantage under the forced-left attention. Overall, the interaural difference in the central conduction time correlates with the ear advantage (non-forced attention) at the beginning of the menstrual cycle. The change in central conduction time between two test times correlates significantly with the change in ear advantage under the non-forced and forced-left attention. Conclusively, the central conduction time depends on the time during the menstrual cycle, which in turn may affect the performance in dichotic listening.

Effects of cisplatin on the auditory function of ovariectomized rats with estrogen deficiency.

CONCLUSION: The ovariectomy in rats does not change their auditory function. However, combining ovariectomy with Cisplatin treatment increases the risk of damaging the auditory function relative to the ototoxic effect caused by Cisplatin alone or ovariectomy alone. OBJECTIVES: The auditory benefit from estrogen depends on a number of factors that make findings among studies controversial. The present study was to examine the impact of Cisplatin, a chemotherapy drug, on the auditory function of ovariectomized rats. METHODS: Thirty-two female rats were assigned to three groups (OVX + C, OVX - C, Sham + C). The rats in the OVX + C and OVX - C groups received bilateral ovariectomy, and those in the Sham + C group received a sham surgery with intact ovaries. After 6 weeks the rats in the OVX + C and Sham + C groups were then treated with Cisplatin for 4 days, but not those in the OVX - C group (control). The auditory function was measured with DPOAE SNRs and ABR thresholds before the surgery and after the Cisplatin treatment. RESULTS: The OVX + C group had significantly decreased the DPOAE SNRs and increased the ABR thresholds relative to the Sham + C group at stimulus frequencies between 2-8 kHz, and the Sham + C group also had worse auditory function than the OVX - C group.