Not surprisingly, physical CDs and vinyl records are no longer the most common formats of music used by U.S. consumers. Digital music, whether it be downloaded or streamed, is more commonly purchased and listened to by these consumers. In addition to music, consumers also have the option of listening to audio podcasts available from the Internet.

As more and more consumers download or stream audio on their phone over a mobile broadband connection, additional traffic will be added to the mobile data network. Currently, half of consumers who own a smartphone report using their smartphone to purchase and download digital music. Additionally, 40 percent of those consumers who reported streaming music when they are away from home use their smartphone to do so.

"Because one third of the data on the 3G/4G mobile network is audio, the listening habits of U.S. consumers are of interest," said Iain Gillott, president and founder of iGR, a market research consultancy focused on the wireless and mobile industry. "These smartphone users who are downloading or streaming music over their 3G/4G mobile broadband network are further challenging the capacity of the mobile data networks."

iGR's new market research report, U.S. Consumers' Listening Habits: Digital Downloads and Streaming, provides details on the formats of music purchased by consumers, the frequency of consumers' digital downloads and streaming, and the devices used.

Some of the key findings discussed in the new research include:

• A digital download is the most common format of purchased music.
• Users of a mobile phone with the Android operating system are much more likely than users of phones with Apple iOS to buy music in a physical format.
• Those respondents who currently own a smartphone are significantly more likely than those with a basic phone to purchase their music from iTunes, Google Play or an online music service.
• 18-34 year olds are the most likely age group to download audio podcasts.
• 62 percent of U.S. consumers stream music and while at home the laptop is the most popular device for streaming music.
• The smartphone is the most popular device used to stream music at locations other than work or home, such as bookstores, gyms, or buses.

Respondents who currently use a smartphone with the iOS operating system are much more likely than users of Android phones to stream music on their smartphone or tablet.