Using the CLOX Drawing Task to Educate the Public of the Effects of Hearing Loss

We describe a task used to educate the public on the importance of hearing and the experience of hearing loss. During an open day at Nottingham University, participants were presented with verbal instructions (with or without a background masker) and asked to draw the image of a clock face as accurately as possible. Poorest performance was observed when the instructions were presented with a background masker. We suggest that the task could be applied effectively by healthcare professionals who aim to educate younger individuals of the difficulties associated with hearing loss.

Examples of the clocks drawn in each condition are shown in figure 1. These examples show clear differences between conditions with some participants producing images where they had recognised the word`hands', but failed to recognise that the image was a clock when the masker was presented (see figures 1c and 1e).
Scores were computed by two markers using a revised version of the scoring system of Royall et al (1998). A point was given for each item, and a score out of 16 was calculated for each drawing (see table 1 for the list of items in the scoring system). The markers (authors CF and SS) were not made aware of the true purpose of the study or method until they had completed the scores for each drawing. A mean score out of a maximum score of 16 for each drawing produced the following scores: in the no-masker condition, the mean score was 15.85 (SD 0X42); in the medium-difficulty condition, the mean score was 11.55 (SD 4X08); in the high-difficulty condition the mean score was 7.95 (SD 7X95).
Analysis of the scoring system using a`one-way' analysis of variance (speech condition with three levels, no masker, medium difficulty, and high difficulty) showed a significant difference between the three conditions (F 2 32 15X16, p 5 0X05). A further a posteriori analysis, with a Bonferroni correction, showed that there was a significant difference between all three groups ( p 5 0X05). Therefore, the presence of the maskers affected the ability of listeners to correctly follow the instructions. Furthermore, the highdifficulty condition made it particularly difficult to follow the instructions in comparison to the medium-difficulty and no-masker conditions.
To assess performance for each instruction individually and to establish whether performance was poorer because participants had difficulty following a particular instruction, the list of items in the scoring system that assessed performance for each instruction was grouped together (see table 1).  Figure 2 shows the percentage of attributes correctly drawn for each instruction and condition. If the no-masker condition showed poorer performance for any of the instructions provided to the participants, this would suggest that some of the instructions were ambiguous. However, this was not the case, with almost ceiling performance (average 95%) in the no-masker condition. Given that performance in the masked conditions was poorer, the differences in performance between conditions can be attributed to the presence of the masker and not the instructions. Furthermore, performance decreases as a function of the level of the speech presented in each condition, with worst performance in the high-difficulty (lowest SNR) condition.

Instructions
Items used to score each instruction (1 point for each item) In summary, we aimed to develop a task with the potential of informing the public about the importance of hearing and potential risks involved in developing noiseinduced hearing loss. The target population for this type of intervention would include children and teenagers. Younger children may not have developed the semantic abilities necessary to draw the complex object used in the current study. In order to successfully deliver this intervention to children, the images should be age-appropriate and familiar (eg draw a tree or house). The simplicity of the task and scoring system suggest that it could be used in any educational setting. Particularly, teachers could adopt this task in classrooms or during undergraduate tutorials to explore the function and importance of the auditory system. Providing participants with the opportunity to hear the instructions again, once the task is complete, reinforces the inability to understand speech in noisy environments that has an immediate impact. Health organisations could adopt this task to reinforce the issues regarding hearing difficulties in noisy environments with the potential to change attitudes toward hearing loss.