Purpose: This study investigated the readability, suitability, and quality of online Single- Sided Deafness (SSD) information available in English.

Method: Four search terms (“Deaf in one ear”, “Can’t hear in one ear”, “One sided hearing”, and “Loss of hearing in one ear” were searched for using 21 country specific Google domains. Of each domain, the first ten relevant webpages were selected. Their country of origin, type of organisation that published them and whether HONcode certification was present or not was recorded. In total, 63 webpages were assessed after duplicates and irrelevant webpages were removed. Readability was measured with the SMOG, FOG and F- K formulas, suitability was measured with the SAM+CAM, and quality was measured with the PEMAT, DISCERN, and a plain language checklist.

Results: Online information on SSD was found to have high readability levels, and adequate suitability levels. Levels of content quality were shown to be moderate by DISCERN, with moderate to superior levels for understandability and poor to moderate actionability as shown by PEMAT. Content had good plain language use as shown by the plain language checklist. Neither country of origin nor organisation type had a significant effect on readability, suitability, or quality.

Conclusions: Access to quality information on SSD can have an effect on patient understanding and health outcomes, therefore this information must be useful and cater to a broad audience. The usefulness of online information on SSD can be indicated by readability, suitability, and assessment of the quality of its content. There is a need for revision of existing online information on SSD and/or development of new material that is readable, suitable, and of good quality. This is necessary to facilitate education on causes, symptoms, and appropriate treatment options for SSD and to encourage taking action towards good health outcomes.