Stimuli were presented via circumaural headphones (Sennheiser HD650, Hanover, Germany) placed around and over behind-the-ear CI sound processors (Goupell et al., 2018a (link)). During unilateral testing, the processor on the opposite side was removed or muted.
Testing occurred in a sound attenuated testing booth (International Acoustics Co., Bronx, NY). The stimulus level began at 65 dB-A, and the volume was then adjusted to a comfortably loud and interaurally balanced listening level. Adjustments were made primarily to the volume in the poorer ear (better-ear exceptions: P01: upward, P08 and P05: downward) and changes were limited to ±5 dB for a maximum of 70 dB-A. Level adjustment was done exclusively at the beginning of the session using the baseline programs and a recorded sentence with the same average root-mean-square amplitude as the test stimuli. Tasks were run using software developed for MATLAB (Mathworks, Natick, MA) running on a personal computer.
Testing occurred in a sound attenuated testing booth (International Acoustics Co., Bronx, NY). The stimulus level began at 65 dB-A, and the volume was then adjusted to a comfortably loud and interaurally balanced listening level. Adjustments were made primarily to the volume in the poorer ear (better-ear exceptions: P01: upward, P08 and P05: downward) and changes were limited to ±5 dB for a maximum of 70 dB-A. Level adjustment was done exclusively at the beginning of the session using the baseline programs and a recorded sentence with the same average root-mean-square amplitude as the test stimuli. Tasks were run using software developed for MATLAB (Mathworks, Natick, MA) running on a personal computer.
