Voice communications using cellular networks from 2G to 3G/LTE is with us for a long time, but does it makes sense to use voice on locations powered by batteries (low power) with LTE-M service as well? In comparison NBIoT is used for even lower powered applications and due to very low bandwidth can’t support voice. According to the chip vendors and two major USA telcos LTE-M + voice makes sense. Potential applications would be smart alarm panel or maybe in the industry vertical where a remote sensor can (apart from sending some data) be used as a voice interface from where a worker can make calls to the central office. Other applications are in B2C market where users can interact with devices similar to Amazon Alexa. Another application could be authenticating user via voice or sound patterns. Currently Verizon has launched the service and more information can be found here.