1. Consider the cost-effectiveness of the audiometer , and what specifically you will be using it for.. Buyers should consider units that are easy to operate, particularly in screening programs where operators may have less training and experience.
2. Speech eudiometry is not a recommended feature. Because of this, pure-tone audiometers, at minimum, should be capable of testing at frequencies of 500 to 6,000 Hz.
3. Standard clinical eudiometry testing is performed over a range of 250 to 8,000 Hz. Although not required, bone-conduction testing for annual or baseline audiograms can be useful in determining diagnosis in a clinical setting.
4. The frequency accuracy of the audiometer should be within 3% for optimal results; within 1% accuracy for some clinical applications.
5. Audiometers should be at least type 3 as specified by ANSI S2.6-1996. In addition, type 1 may be required under certain conditions and are recommended for clinical environments where a full range of testing applications must be met.
6. A clinical audiometer might require speech-testing functionality. To do so, the audiometer should be designated at least type C. Standardized specially prepared speech material from tape or CD input is recommended to microphone input, this will help maximize consistency in testing results.
7.Half-octave or octave steps should exist on the audiometer. Half-octave frequencies are needed to verify consistency in a subject's hearing level when exposed to an octave.
8. Earphones are a vital addition to any audiometer. If your audiometer needs to deliver a signal to the subject, make certain the earphones contain one earphone for each ear.
9. Insert earphones are preferred because they are generally lighter and provide a better fit than supra aural earphones. They offer greater protection against the signal being heard by the opposite ear.
10. Free-field testing is not normally recommended for screening purposes. It may be a good alternative to earphones when testing small children who may not tolerate earphones. It is also used in certain hearing-aid assessments.
11. To ensure that one ear is not compensating for the other during the test, masking noise should be available for clinical testing.
