Level I: The most economical digital hearing aids provide a clearer, crisper sound and have more automatic features than their analog predecessors. Examples include the Resound Essence, Oticon Hit, Starkey E Series, Hansaton Style, and others. Price: $995 to $1295 per instrument.

Level II: These instruments are more flexible than their Level I counterparts with more processing channels and better programmability. More channels result in more precise amplification for a natural and comfortable sound. Programmability is the ability to change the hearing aid in the office to suit each individual's lifestyle. Examples include the Resound Live 5, Widex Real, Starkey S Series 5, Oticon Intiga 6, Phonak Cassia, Audeo S Smart III, and others. Price: $1395 to $1795 per instrument.

Level III: Hearing aids at this most popular level are more automatic and flexible with many available options. Level IV aids usually have many frequency channels, multiple user programs or settings, and automatic directional microphones. Directional microphones will amplify sound only from the direction the wearer is facing. They are especially helpful in noisy areas such as restaurants. Examples include the Resound Alera 7, Starkey S Series IQ, Phonak Audeo S Smart V, Widex Clear, Oticon Intiga 8, and others. Price: $1895 to $2295 per instrument.

Level IV: These hearing aids use the most sophisticated technology and processing strategies available and are the "flagship" units for each manufacturer. The emphasis at this level is maximum flexibility in performance with special attention to improving hearing in background noise and other adverse situations. Often key features at this IV level are not available on other levels. The newest hearing aids will communicate with each other for more realistic binaural hearing. Examples include the Resound Alera 9, Oticon Agil Pro, Siemens 701 designations, Phonak Ambra and IX series, Starkey X and S IQ Series 9, and Widex Clear 440. Price range: $2295-$2995 per instrument.