All are a type of audio-visual aids except

Flannel graph: Audiovisual aids: No health education can be effective without audiovisual aids. Auditory aids: radio, cassette tape-recorder, microphone, amplifier, earphone, public address system, disks Visual aids: Not requiring projection: Chalk-bored, leaflets, posters , chas, flannel graphs, exhibits, models, specimens, diagrams, photographs Requiring projection: Slides, filmstrips, overhead projector, epidiascope Combined A-V aids : Televsion, sound films (cinema, synchronized slide-tape combination, multimedia, videotape, drama, skits Ref: Park 25th edition Pgno: 926