The unique design of these inert earphones eliminates interference with ERP / EP measurements. The flat frequency response referenced to the sound field provides predictable performance over the frequency spectrum, which is key for research applications. 70+ dB isolation between ears: reduces the need for masking, and the foam ear-tip eliminates the collapsed ear canal problem while providing 30+ dB external noise exclusion.
The device is used to accurately attenuate a sound signal in steps of 1 dB. If the input signal is e.g. attenuated by 20 dB then the output signal amplitude is 1/10th of the input signal amplitude. Such an accurate control of damping is necessary in the field of e.g. objective audiometry.