Hearing faculty testing and apparatus therefor

Hearing faculty testing apparatus comprising:

• an aural probe for insertion in a subject's external ear canal,
• electroacoustic transducer means mounted in said probe for projecting sound into said canal and for responding to reactions produced by said sound in said canal,
• a pulse generator for repeatedly activating said transducer means to project a sequence of transient sounds,
• time-gating means responsive to both said generator and said transducer means for detecting delayed reactions produced by said sounds only within a period of from 5 to 20 ms following termination thereof to detect the reactions produced exclusively by return of said sound from within the inner ear of said subject, and
• analyser means responsive to said detecting means for processing the detected echo signals at least by averaging a sequence thereof.

Hearing faculty testing apparatus comprising:

• an aural probe for insertion in a subject's external ear canal,
• electroacoustic transducer means mounted in said probe for projecting sound into said canal and for responding to reactions produced by said sound in said canal,
• a pulse generator for repeatedly activating said transducer means to project a sequence of transient sounds,
• time-gating means responsive to both said generator and said transducer means for detecting delayed reactions produced by said sounds following termination thereof,
• said time-gating means being constructed to detect the reactions produced by return of said sounds from within the subject's inner ear substantially only during a period from 5-20 ms, and
• analyser means responsive to said detecting means for processing the detected reaction signals at least by averaging a sequence thereof.