ABSTRACT
This chapter focuses on the tests that require skilled observation and recording of the child's 'functional' responses to speech or 'non-speech' sound stimuli. The use of behavioural observation audiometry in infants under 6 months has been largely superseded by the availability of electrophysiological techniques. Frequency-modulated warble tones with stimulus duration of 1–3 seconds are the preferred option, providing low-, mid- and high-frequency-specific signals delivered by means of portable soundfield noise generators, loudspeakers, insert earphones or bone conductor, used in a similar arrangement to that described for Visual reinforcement audiometry. The number of reliable responses elicited by distraction testing may be limited, particularly in children over 12 months who may habituate to the test. The techniques employed in performance testing naturally lead into pure tone audiometry as the child matures. A wide range of speech discrimination assessments are available and may be valuable in verifying hearing thresholds and in assessing the effectiveness of hearing aids or auditory implants.
