Although autism and hearing loss may seem unrelated, they can sometimes show similar behaviours, which may lead parents or teachers to initially mistake a child with hearing loss for a child with autism. Despite these similarities, the underlying reasons are very different.

1. Social Interaction

For children with autism, difficulties in social communication and interaction are a core characteristic. They may show little interest in people around them. Because they often find it hard to understand others' feelings, perspectives, and unwritten social rules, they may display behaviours that seem socially inappropriate, making it difficult for them to participate in group activities. For example, when someone calls their name, they may not respond. This can sometimes make others think they cannot hear, when in fact the child may simply not be interested or may not understand that they are expected to respond when their name is called.

For children with hearing loss, before they are fitted with hearing devices, they may not realise that others are speaking to them because of their reduced hearing ability. As a result, they may not respond and may appear socially withdrawn. Even after wearing hearing aids, their hearing is usually not fully restored to 100%. If someone speaks too softly or too quickly, they may still have difficulty understanding speech, which can affect communication and social relationships.

2. Language Development

Both groups of children also have a higher likelihood of language delay, though the reasons differ.

Children with autism often seem to live in their own world and may have reduced motivation to communicate. Even when they talk with others, they may prefer discussing topics that interest them and show little interest in other topics. Because of this, they may receive less varied language input. Some children with autism may be able to memorise many complex words, but they may struggle to use language for functional communication. For example, using language to make requests, express needs, or share ideas.

Children with hearing loss, before receiving hearing support, may experience the world as very quiet or with only limited sound. This reduces opportunities for incidental learning. Incidental learning happens when children pick up new words or sentence structures naturally by listening to conversations around them. For example, when family members are talking and the child overhears the conversation, they may learn new vocabulary from it. Children with hearing loss may miss many of these opportunities.

How Can We Tell the Difference?

Children with autism often show additional characteristics that are less common in children with hearing loss. For example, they may:

• resist physical contact
• show sensory needs e.g. sounds, smells, touch, or light
• have very restricted interests
• show strong insistence on rules or routines, sometimes creating their own rules and becoming upset if others do not follow them
• feel anxious about unexpected changes, such as a sudden change in daily plans
• have difficulty adapting to new environments

In contrast, children with hearing loss usually do not show these behavioural patterns.