BSA Recommended Procedure: Pure-Tone Air & Bone Conduction Audiometry

This document outlines the ideal strategies and guidance for effective pure-tone audiometry, a widely used technique in audiological contexts. It covers descriptors for pure-tone audiograms and the recommended format for audiogram forms, emphasizing the importance of cleaning transducers, audiometers, and response buttons. The document highlights the necessity of meeting current calibration requirements and performance standards for audiometers, as outlined by the British Society of Audiology (BSA). It details the test environment requirements, including clear visibility of the subject's face while preventing the subject from seeing or hearing the tester. Preparations for testing involve effective communication with the subject, considering age, language skills, and potential communication difficulties. The report addresses potential measurement issues, such as false air-bone gaps, and suggests using insert earphones to mitigate these problems. It also covers the importance of masking to identify which ear is responding during bone-conducting testing, and the proper calibration of masking noise as per BS EN ISO standards. The procedures for both air-conduction and bone-conduction audiometry are described, including tone timing, threshold determination methods, and masking techniques.

Audiology
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The main motive of this document is to describe ideal strategy and guidance for effective pure-
tone audiometry which has been used in maximum audio logical context. The other topic which
has been covered is descriptors for pure tone audiograms and the format which has been
recommended for audiogram forms. It is necessary to clean the transducer, audiometer and the
button which is being used to respond. The relevant and current calibration requirements and
performance must be met by audiometers (British Society of Audiology, 2011). For the test
environment, the tester must be able to see the face of the subject clearly but the subject must not
be able to see or hear the tester while adjusting audiometer control. The test result can be
affected by excessive ambient noise and this noise must not exceed the level which has been set
out in the standards of BS EN ISO. There are some preparations which need to be followed for
testing. The tester must follow a strategy of effective communication with the subject. This
considers the age of the subject, language skills, hearing and other difficulties in communication.
Any likelihood in supra-earphones can lead to measurement issue which could be a false air-
bone gap. Inserting earphones can help in avoiding most of the problems. Permission needs to be
taken from the subject for any exposure which may make a loud noise and cause temporary hear
loss. Instructions need to be clear and must contain all the relevant details about the task. There
are three transducers which are being used in air-condition audiometry: insert earphone, supra-
aural and circum-aural (Gilbert, 2008).
Test order starts with better hearing power at 1000 Hz and the timing of tone which varies
between 1 and 3 seconds. The timing of each tone must not be predictable and tester has the
responsibility for it. The tester should continue with the signal until the subject responds. There
are some methods which can help in finding a threshold. It requires following a response which
is satisfactory and positive (Russell & Cohn, 2012). The level of the tone 10 dB needs to be
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reduced and tone in 5-dB needs to be increased unless not getting any further response. Masking
is required in order to identify which ear is giving a response to bone-conducting testing. The
bone vibrator use to place on the worse hearing ear and it must be kept near to the pinna but it
should not touch it. The timing and instructions for the test are the same as for a-c audiometry.
Earphones make sound limited to one ear at a time but it is not necessary that the intended is
detecting the sound. It is easy to overcome from the cross-hearing issue by raising the hearing
entrance of the not test ear. As per the BS EN ISO 369-4 masking noise must be calibrated for an
effective masking level. If the noise is not getting calibrated as per the effective masking level in
that case the entrance of masking noise needs to be figured out. In this test also a sound can be
noticed during the test and the button needs to be pressed just after hearing the sound (Valente,
Hosford-Dunn & Roeser, 2008).
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References
British Society of Audiology. (2011). Pure-tone air-conduction and bone-conduction
threshold audiometry with and without masking (4th ed.). The United Kingdom.
Gilbert, J. (2008). Medical Device Materials IV (1st ed.). Materials Park, OH: ASM
International.
Russell, J., & Cohn, R. (2012). Audiology (3rd ed.). U.S.: Lennex Corp.
Valente, M., Hosford-Dunn, H., & Roeser, R. (2008). Audiology (4th ed.). New York:
Thieme.
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