Division of the stapedial tendon results in noise-induced damage to the inner ear

The effect of simultaneous exposure to cigarette smoke and noise on distortion product otoacoustic emissions in rats

Cigarette smoking is a possible risk factor for hearing loss. However, the impact of simultaneous exposure to noise and smoke on hearing has remained controversial. This study investigated the combined effect of exposure to cigarette smoking and noise on hearing loss. Three groups of male Wistar rats (275 ± 25 g) were subjected to white noise (102 ± 0.5 dB), cigarette smoking (20 cigarettes), and both cigarette smoking and noise for 8 h and 10 days inside the exposure chamber. The control group was exposed to neither noise nor smoke. Distortion product otoacoustic emissions (DPOAE) were measured before any intervention, and it was repeated 1, 7, and 21 days after the last exposure. One-day postexposure to noise, cigarette smoking, and both cigarette smoking and noise, the mean of DPOAE amplitudes decreased significantly ( p < 0.05) between, respectively, 5.7-30.7, 1.5-7.5, and 5.2-32.6 dB within the frequency range of 4620-9960. Temporal DPOAE change in rats exposed to noise or both cigarette smoking and noise was not significantly different ( p > 0.05). DPOAE amplitudes returned to the baseline values in the group subjected to smoking 21 days postexposure. The most permanent change was observed in rats exposed to both cigarette smoking and noise. Accordingly, simultaneous subacute exposure to noise and cigarette smoking increases the effect of noise on permanent hearing loss. Therefore, smoking workers exposed to noise might be at a greater risk of developing hearing loss, and it is recommended that authorities in charge take note of this evidence.

Repeatability of transient-evoked otoacoustic emissions in young adults

Background

The aim of this study was to evaluate the repeatability and variability of TEOAE characteristics in hearing screening tests performed under practical conditions on normal subjects.

Material/Methods

A group of 11 young, normal-hearing subjects aged 19–24 years was tested. They were examined otologically and audiologically prior to the tests and no ear pathologies were found. Responses were acquired with a commercially available instrument (Integrity, Vivosonic Inc.) using a standardized OAE protocol. The TEOAE tests were repeated 3 times in each subject at random intervals within 24 h. The analyzed parameters of interest were: (i) whole wave reproducibility (WWR) and; (ii) signal-to-noise ratio (SNR).

Results

WWR and SNR did not differ significantly among the 3 measurement sessions. In most cases the differences in WWR among measurements were around 1–2% and for SNRs they were 1–4 dB SNRs and were highest in the 1–2 kHz range. TEOAE-based tests can be useful tools for hearing screening.

Conclusions

The tests can give reliable results provided that adequate procedures are used and low-noise conditions are ensured. The tests are best complemented with other examinations to widen the range of ear pathologies able to be detected.

Determination of correlation among heart rate variability, left atrium global strain, and nighttime blood pressure among patients with tinnitus

Background

We aimed to examine the correlation among nighttime blood pressure, heart rate variability, and left atrium peak systolic global longitudinal strain among patients with subjective tinnitus.

Material/Methods

Eighty patients with tinnitus were assigned to Group 1 and 80 healthy individuals were assigned to Group 2. Clinical blood pressure measurements, ambulatory blood pressure monitoring, and Holter electrocardiography monitoring were performed. All of the cases included in the study were examined with conventional echocardiography and 2-dimensional speckle tracking echocardiography.

Results

Mean nighttime systolic blood pressure (130.3±5.4) and mean nighttime diastolic blood pressure (82.8±3.9) in Group 1 were higher than in Group 2 (125.1±5.4 and 80.7±4.7, respectively) (p<0.05). Mean heart rate in Group 1 was significantly lower than in Group 2 but there was no statistically significant difference between the groups in terms of heart rate variability parameters and left atrium peak systolic global longitudinal strain values (p>0.05).

Conclusions

Nighttime systolic blood pressure and nighttime diastolic blood pressure were higher among the patients with tinnitus. In light of these results, we can conclude that both clinical blood pressure measurement and ambulatory blood pressure monitoring are important for patients with tinnitus.