Smart speakers aren’t just the latest fancy home appliance—they’re changing the ways in which American consumers behave and even think. In a keynote address at Advertising Week today, Tom Webster, Edison Research’s vice president of strategy, revealed just how significant of an effect Amazon Echo and Google Home have on their users.

According to their study, which surveyed 1,620 American households, 40 percent of smart-speaker owners reported that the device had a major impact on their lives and 42 percent claimed to have purchased multiple. Edison’s interviews revealed that users find themselves listening to significantly more audio content, from music to podcasts to audiobooks.

Though this rise in audio consumption cannibalizes from radio, interviews showed that smart speakers most frequently replaced mobile device usage. Some respondents even reported choosing audio content over television.

Twenty-eight percent of respondents said their smart speaker drove them to pay for a music subscription service, and several interviewees reported switching from Spotify to Amazon Prime because of their speaker.

Families with children were the most affected by their smart speakers, with 42 percent reporting that they found the device “essential.” One person that Edison interviewed referred to his Echo as his “girlfriend when the wife isn’t around.”

“At a minimum, we can say that these devices have become companions, if not full-ranking members of the household,” Webster stated.

Webster described the experience of using a smart speaker as strange but familiar, and referenced Star Trek not once, but twice to explain how pervasive the Zero UI experience has been in America’s cultural lexicon.

Their research confirmed his claims. While young people remain the fastest adopters, with people 35 and younger comprising 52 percent of the heaviest users, the ease of use of these devices meant that 27 percent of medium-heavy owners—ones who regularly use their smart speakers for six to ten different tasks—were 55 and older.

However, not everyone is pleased with the current state of voice-controlled devices. Of the 820 survey respondents who did not own smart speakers, the top five reasons for not purchasing one were all related to privacy. Even more concerning, 63 percent reported wariness over government surveillance from the always-on listening devices. Webster himself admitted to fearing the possibility of someone shouting into his apartment and fraudulently ordering a herd of cattle.

Overall, the explosive growth of smart speakers offers major potential for marketers. Sixty-five percent of survey respondents claimed to have used one to place an item in their shopping cart, and 58 percent have bought an item they had never purchased before.

Citing Star Trek again, Webster described using Zero UI technology as strange but familiar and anticipated the devices as heralding the dawn of the science fiction era he grew up expecting.