an exam for an irregular vulnerability to boisterous noise. The person listens to 2 tones, both the identical frequency listened to in a back and forth manner between the two ears, with the force of the noise at one ear being positioned at a degree 20 dli above the second noise. If the person understands the 2 noises as having identical volume levels, it has demonstrated that one of their ears are somewhat more vulnerable to volume- a measure of subjects so very strongly comparable to a different measure that they are thought to be a unique variation of the very same exam. Commonly referred to as alternate test form or parallel form.