Development and application of a code system to analyse behaviour in real life listening environments

Numerous studies showed that different hearing aid (HA) algorithms improve speech intelligibility in typical lab situations as measures of clinical efficacy. From the perspective of auditory ecology, it remains obscure to what extent these results really allow for estimating the outcome in listening situations in real life. One promising tool is the observation of participants behaviour induced by different HA settings. We developed an annotation system for coding the behaviour related to the framework of the International Classification of Functioning, Disability and Health (ICF) in iterative steps. The first inputs were derived from a series of lab studies, using virtual acoustics. It was shown that different directional modes of HAs influenced real life behaviour. First indications of activity limitation according to ICF (d3504 ‘Conversing with many people’) were found. Additionally, the behaviour of users in real life was described by means of ‘ethnographical walks’ outside of the laboratory using field notes. We identified further behaviour patterns addressing spatial awareness. The conversation related ICF sub-categories were validated by analyses of inter-rater reliability (IRR). The outcome of these analyses led to a reformulation of an annotation/coding system for the usage on tablet PCs for instantaneous coding of the test persons behaviour in real life.