A wide range of technology and a host of features are available in each hearing aid style. The cost of hearing aids generally depends on the technology and the number of features the instrument has and not necessarily on the style selected. Today's digital hearing aids are typically offered in various levels such as basic or entry-level to advanced or premium-level. Within each level, different technology and features are available.
Basic digital hearing aids generally require the wearer to make some manual adjustments in certain listening environments such as turning a volume control up or down, or pushing a button to change listening programs. In contrast, a premium or more advanced hearing aid responds automatically to changes in the listener's environment, making changes based on the signals being detected by the hearing aid. The hearing aid wearer is not required to make any manual changes. As the level of the technology increases in hearing aids, so do the availability of advanced features.