ABSTRACT
The effects of stimulus duration and stimulus off time on the thresholds of hearing and the acoustic reflex were investigated in 10 normal-hearing subjects and 10 subjects with sensorineural hearing loss. A 1000-Hz stimulus with on-off times of 500-500 msec and 30-30 msec was used to obtain hearing sensitivity and acoustic reflex thresholds via a tracking method. Auditory threshold was poorer for the 30-30 msec tone than the 500-500 msec stimulus in both groups. Using the different stimuli, no significant difference in acoustic reflex threshold was observed in either group. These results suggest that the addition of a short off time modifies the previously observed effects of both duration and off time on the acoustic reflex and auditory threshold.
Subject(s)
Audiometry/methods , Auditory Threshold , Ear, Middle/physiology , Reflex , Adult , Auditory Threshold/physiology , Deafness/physiopathology , Humans , Labyrinth Diseases/physiopathology , Reflex/physiology , Time FactorsABSTRACT
Tympanometry and the acoustic reflex constitute a powerful middle ear measurement battery. Together, these measurements provide us with direct objective information about the integrity and mobility of the middle ear system and the status of the sensorineural auditory function. A descriptive analysis of tympanograms involves a consideration of the amplitude and shape of the tympanogram as well as the location of the peak along the air pressure axis. The differential effect of pathology on tympanogram pressure peak location, amplitude and shape as well as on the acoustic reflex provides the capability for the application of this battery in the differential diagnosis of auditory disorders.
Subject(s)
Audiometry/methods , Deafness/diagnosis , Deafness/physiopathology , Ear, Middle/physiopathology , Eustachian Tube/physiopathology , Humans , Pressure , ReflexSubject(s)
Audiometry , Deafness/diagnosis , Occupational Medicine , Referral and Consultation , Humans , United StatesSubject(s)
Acoustic Stimulation , Chinchilla/physiology , Ear, Middle/physiology , Reflex , Animals , Humans , Time FactorsABSTRACT
The poor relationship between hearing loss and ear disease minimizes the effectiveness of audiometry as a technique for the identification of middle ear disorders. Tympanometry has been shown to be a highly sensitive technique for the identification of and differentiation between middle ear disorders. It is particularly useful in a pediatric population where ear disease is so frequently encountered. The interpretation of tympanometry on the basis of a descriptive analysis of tympanograms is proposed as opposed to a coded typing system. Descriptive analysis views the pathological effects of middle ear diseases on pressure peaks, amplitude and shape of tympanograms.
