"Alexa, order more cereal."

Is the world moving from search to sound? It sure seems that way. This year, nearly 36 million Americans will use a voice-enabled speaker at least once a month, a 129 percent increase from 2016, according to a report released last spring by eMarketer.

The proliferation of voice-enabled assistants, such as Amazon's Alexa, Apple's Siri, and OK Google, presents brands with new marketing vehicles to get their messages out. It also underscores the growing importance of audio branding, or how companies use sound and music to define and reinforce brand identity.

People know audio branding when they hear it. Think of Intel's iconic five-note sonic bong, the famous melody of State Farm insurance ("Like a Good Neighbor"), or George Gershwin's "Rhapsody in Blue" scoring United Airlines ads. However, audio branding is not limited solely to corporate jingles, and should not be confused with one-off soundtracks noting a new product or service.