What problem could occur if the battery in a hearing aid is not properly inserted?

When the battery in a hearing aid is not properly inserted, the most immediate and significant problem that can occur is a lack of sound. A hearing aid relies on a properly seated battery to complete its electrical circuit and function as intended. If the battery is inserted incorrectly or is not making proper contact with the terminals, the device will not be able to power on or amplify sound, resulting in silence for the user.

While other issues might arise from a poorly seated or malfunctioning battery, such as static, distortion, or feedback, these problems typically occur within the context of a functioning device. If there is no sound at all, the hearing aid is essentially rendered useless until the battery issue is corrected. Thus, the absence of sound is a direct consequence of the battery being improperly inserted.