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Resumen del manual
Whether you are performing hearing screening in an educational or industrial setting, testing related to the fitting or evaluation of amplification, audiological research, or comprehensive diagnostic assessment, E-A-RTONE® 3A Insert Earphones provide many advantages that can enhance test reliability and minimize or eliminate problems frequently encountered with supra-aural headphones. Because the subject’s external canal is sealed with an E-A-RLINK® foam plug, which functions as a sound delivery system while at the same time attenuating ambient noise, reliable threshold measurement can be accomplished in environments previously unsuitable for hearing testing. Direct coupling also produces much greater sound separation between ears across the test frequency range. Clinically, that means more instances where the need for masking is eliminated, or the level necessary for effective masking is lower. Your average testing time will decrease without sacrificing reliability. The method of clinical masking you use does not need to be altered. Simply substitute the greater inter-aural attenuation values cited in the Obtained Interaural Attenuation table in section 1. of this booklet. E-A-RLINK® foam plugs are available from your distributor in three sizes; a standard (3A) plug that will comfortably fit most adult ear canals, a pediatric (3B) size for small canals, and an extra large (3C) size for very large or surgically altered ear canals. Disposable plugs also insure that sanitary conditions exist for each of your patients, and that periodic cleaning of a headband or cushion is no longer required. The E-A-RTONE® 3A Insert Earphone is offered with three levels (10V, 50V, & 300V) of impedance to match the output of most commercially available audiometers. Your distributor or Auditory Systems can help you determine which version is appropriate for your equipment. E-A-RTONE® 3A Insert Earphones were designed to mimic the frequency response of the TDH type earphone. It is strongly recommended, however, that the (RETSPL) values and procedure cited in the ANSI S3.6 - 1996 Standard be used in recalibration, before initial use, unless your audiometer was purchased with an E-A-RTONE® 3A as the standard transducer, and at least annually thereafter. Measured correction factors can be applied in those cases where it is necessary to alternate between an insert earphone and a supra-aural earphone. This instruction booklet is intended to provide information to allow you to perform hearing testing with your audiometer and E-ARTONE ® 3A Insert Earphones with the confidence that results will be comparable to, or in certain instances more reliable than, measurements performed with supra-aural headphones. Most questions regarding use and calibration of E-A-RTONE® 3A Insert Earphones can be answered by reviewing this booklet and/or ANSI S3.6-1996. For information regarding replacement items, please contact your distributor or Auditory Systems Customer Service at 800/624-5955. Requests for technical assistance, or comments regarding E-A-RTONE® 3A Insert Earphones and E-A-RLINKS® should be directed to Aearo Company Auditory Systems at 317/692-6550. 1 1. Preliminary Procedures for Use of the E-A-RTONE® 3A Initially examine the ear canal for obstruction(s) and evaluate the proper size E-A-RLINK® disposable foam eartip needed to fit the particular ear canal. Although the standard E-A-RLINK® 3A fits most ear canals, for smaller ear canals, the smaller diameter E-A-RLINK® 3B eartips are available. It is important to obtain a good seal and achieve the proper insertion depth. Insertion procedures are the same for the E-A-RLINK® 3A and E-A-RLINK® 3B, but deep insertion may be difficult to achieve in extremely small ear canals. In these instances, a shallow placement will have to suffice. Secure the section of black tubing, which protrudes from the E-A-RLINK® eartips to the sound tube nipple located at the end of the E-A-RTONE® sound tube. Slowly roll the E-A-RLINK® tip into the smallest diameter possible and insert the E-A-RLINK® well into the ear canal (see illustrations). Since the eartips are 12 mm long, the correct insertion depth into the ear canal is obtained when the rear edge of the E-ARLINK ® is 2-3mm inside the entrance of the ear canal. Hold E-A-RLINK® in ear canal until expanded. After the test is completed, remove the E-A-RLINK® eartips and replace with a new pair for the next subject. E-A-RLINK® Full Insertion Shallow Insertion Proper insertion depth is necessary to achieve maximum ambient noise attenuation and interaural attenuation. The graph below depicts interaural attenuation as a function of insertion depth. The described interaural attenuation is obtained for each ear in which the E-A-RLINK® is fully inserted, regardless of whether it is the “sending” ear or “receiving” ear. 2 Hz 125 250 500 1000 2000 4000 8000 -10 dB 0 10 20 30 40 50 60 70 80 90 100 110 Full E-A-RLINK insertion in both ears Shallow insertion in dead ear only...