A ____________ is a device that allows communication with citizens who are hearing impaired and/or unable to verbally communicate, through typing instead of speaking.

A TDD, or Telecommunications Device for the Deaf, is designed specifically to facilitate communication with individuals who are deaf or hard of hearing. This device allows users to type messages back and forth rather than speaking, thus enabling effective communication for those who may not be able to hear or speak verbally. In the context of emergency services, having a TDD ensures that all citizens, regardless of their hearing abilities, have access to critical communication during emergencies.

The other terms listed do not accurately represent a device used primarily for this purpose. DTC (Data Terminal Controller) is not specifically for communication with the hearing impaired. TTD (Telecommunications Device for the Deaf) is often used interchangeably with TDD but is less common in terminology. FRS (Family Radio Service) refers to a two-way radio service, which is unrelated to the communication needs of individuals with hearing impairments. Thus, TDD is the appropriate and correct choice for facilitating typed communication with hearing-impaired individuals.