Testing for Discrimination in Employment Practices

Hypothesis: The velocity response at the contralateral cochlea from bone-conducted (BC) stimulation depends on the stimulation position. Background: BC sound transmission in the human skull is complex and differs from air-conducted sound. BC sound stimulates both cochleae with different amplitudes and time delays influencing hearing perception in a way that is not completely understood. One important parameter is the stimulation position on the human skull. Method: By applying BC stimulation at 8 positions on both sides of 7 human cadaver skulls, the contralateral velocity response of the cochlear promontory was investigated in the frequency range of 0.1 to 10 kHz. Using previous data from ipsilateral stimulation, the transcranial transmission (TT) and effects of bilateral stimulation to one cochlea was calculated. Results: The contralateral transmission from the 8 positions showed small differences, but the TT showed a generally increased cochlear separation when the stimulation position approached the cochlea. The effect of simultaneous bilateral stimulation was calculated, showing a low-frequency negative effect for correlated signals, whereas uncorrelated signals gave 3-dB gain. At higher frequencies, there was less interaction of the combined stimulation because of the greater intercochlear separation. Also, the greatest time difference between ipsilateral transmission and contralateral transmission was at positions close to the cochlea. Conclusion: The stimulation position only slightly affects the amplitude and phase of the contralateral cochlear velocity response. However, because of the great influence from the ipsilateral transmission, a position close to the cochlea would be beneficial for patients with bilateral BC hearing aids.Original Publication:Måns Eeg-Olofsson, Stefan Stenfelt and Gösta Granström, Implications for contralateral bone conducted transmission as measured by cochlear vibrations, 2011, Otology and Neurotology, (32), 2, 192-198.http://dx.doi.org/10.1097/MAO.0b013e3182009f16Copyright: Lippincott Williams and Wilkinshttp://www.lww.com

Factors That Introduce Intrasubject Variability Into Ear-Canal Absorbance Measurements

Wideband immittance measures can be useful in analyzing acoustic sound flow through the ear and also have diagnostic potential for the identification of conductive hearing loss as well as causes of conductive hearing loss. To interpret individual measurements, the variability in test- retest data must be described and quantified. Contributors to variability in ear-canal absorbance-based measurements are described in this article. These include assumptions related to methodologies and issues related to the probe fit within the ear and potential acoustic leaks. Evidence suggests that variations in ear-canal cross-sectional area or measurement location are small relative to variability within a population. Data are shown to suggest that the determination of the Thévenin equivalent of the ER-10C probe introduces minimal variability and is independent of the foam ear tip itself. It is suggested that acoustic leaks in the coupling of the ear tip to the ear canal lead to substantial variations and that this issue needs further work in terms of potential criteria to identify an acoustic leak. In addition, test-retest data from the literature are reviewed

Seeing the talker’s face supports executive processing of speech in steady state noise. Front

Listening to speech in noise depletes cognitive resources, affecting speech processing. The present study investigated how remaining resources or cognitive spare capacity (CSC) can be deployed by young adults with normal hearing. We administered a test of CSC (CSCT