All hearing aids receive two “IP” ratings from the International Electrotechnical Commission to determine how resistant they are to dust and water. Here are what the two numbers mean:
● The first digit rates the degree of protection against debris, such as dust or sand, and is rated on a scale of 1-7.
● The second digit indicates how resistant the electrical device is to moisture and is rated on a scale from 1-8. Below you can find a scale relating to the water-resistant rating.
For example, a hearing aid with an IP67 rating means it is highly protected against solid objects such as sand or dust and has been tested to work for at least 30 minutes in water less than three feet deep.