Which of the following is an audio-visual aid?

Audio-visual aids form one of three broad categories of teaching aids, classified by which sense(s) they engage: Audio aids (radio, tape-recorder, gramophone) stimulate hearing alone; Visual aids (charts, models, printed pictures) stimulate sight alone; Audio-visual aids stimulate hearing AND sight simultaneously, combining sound with moving or synchronized visual images (television, films, video, multimedia presentations).

Among the given options, a tape-recorder reproduces sound only, with no visual component, so it is classified purely as an audio aid. Radio broadcasts sound only, again with no visual element, so it too is an audio aid rather than audio-visual. Television, however, transmits synchronized moving pictures together with sound, engaging both hearing and sight at the same time, which is precisely the defining feature of an audio-visual aid.

• tape-recorder: sound only, no visual channel → audio aid, not audio-visual

• Radio: sound only, no visual channel → audio aid, not audio-visual

• Television: sound plus synchronized visuals together → audio-visual aid

• “All of these”: incorrect, since tape-recorder and radio lack any visual component, so the category cannot cover all of them

Therefore, Television is the audio-visual aid among the options.