HD radio promises to offer higher sound quality for both AM and FM stations. The digital transmission eliminates the crackling heard on analog radio, according to Clear Channel Music. With an HD radio, you can receive both analog and digital signals so if a station does not offer a digital transmission, you can still listen to the analog version. However, if a digital signal is offered, the HD radio will automatically select that frequency.
According to CNET, digital radio stations use between 1 and 10 percent of the bandwidth required by analog stations, which means more information can be transmitted. Some stations have taken advantage of this by offering substations, which are additional listening options on the same station. With an analog radio, you do not have access to those stations. In addition, the digital transmission allows your radio to display information about the song, such as the artist and title, or important weather warnings without interrupting the broadcast.
The cost of HD radio is a disadvantage over analog radios because of the cost to purchase and install an HD radio. However, prices for HD radios have dropped significantly since its inception and some car manufacturers, including Audi, have announced that they will start making HD radios standard. However, cost is an advantage over satellite radio because you do not have to pay any subscription fees. The only cost for HD radio is the cost of the unit.