What is essential for determining the battery life of a hearing aid?

Determining the battery life of a hearing aid fundamentally relies on the current draw of the hearing aid because it is a key factor in how much power is consumed during operation. The more power the hearing aid draws, the faster the battery will deplete, regardless of the battery's size or chemistry.

While the type of battery can influence capacity and performance, it is not the sole determinant of battery life. The frequency response of a hearing aid relates more to its performance in sound processing rather than its energy consumption. The manufacturing date of the battery can impact its freshness and performance, but it is not directly related to how much current the device uses during its operation.

Therefore, understanding the current draw provides direct insight into how long a battery will last under specific conditions, making it essential for accurately predicting battery life in hearing aids.