To talk to the subject, we use a standard unidirectional microphone that must be turned off at the start of experiments to prevent feedback. To hear the subject, we have installed an Audio-Technica (Stow, OH) ATM10a omnidirectional condenser microphone using a pass-through in the MSR; since the microphone is functionally inside the MSR, a condenser mic is necessary to eliminate RF noise. We also have an OptoAcoustics (Or Yehuda, Israel) fiber-optic microphone that we use to record voice-onset triggering.
Input from the subject’s mic is fed into a Eurorack (Behringer; Willich, Germany) UB502 mixer preamplifier. The mic we use to communicate to the subject is fed into a MACKIE (Woodinville, WA) 1202-VLZ3 Premium mic/line mixer.
Output is provided using E-A-Rtone (AEARO Company; Indianapolis, IN) 3A insert earphones. Two 50 ohm amplifiers for the E-A-Rtone system direct the stimulus via silicon air tubes that are approximately 1.5 m (5') in length.