In order for the volume to be accurately quantified, an artificial ear must be used to measure sound level. If a loudspeaker is to be used instead of headphones, an audio amplifier will be needed to produce sufficient volume. WN White Noise Generator Direct electrical stimulation. The SHK2 digitally controlled shock generator may be used to directly stimulate the nerve above the eye. Electrodes should be positioned in the opposite plane to the EMG measurement electrodes.
Stimulus electrodes positioned above the eye.
The RL8 relay coupler may be connected to a solenoid valve which controls the flow of air from a compressed air cylinder. The air tube is then positioned to direct the puff just below the eye. The solenoid valve should be positioned such that the noise it makes is not audible to the subject. While air puff is a more involved technique mechanically, it produces excellent reliability of response. RL8 Relay unit Lamp flash.