He spoke with “Marketplace” host Kai Ryssdal about the increasing importance of sound in the modern era. In an ongoing podcast called “ Twenty Thousand Hertz,” Dallas Taylor tells the stories behind recognizable sounds such as NBC’s chimes, Netflix’s startup sound and HBO’s theme music. As more people interact with brands in digital spaces, companies are using sound to their advantage. Whether it’s a carefully crafted commercial jingle or the voice of Siri, sound can play an important role in a company’s brand identity.