Audio media includes radio broadcasts and recordings that transmit sound through waves. Radio broadcasts can reach large audiences and be recorded to ensure accurate presentations, though they only allow one-way communication. Recordings allow two-way interaction and can be reused. Audio is effective for storytelling, stimulating imagination, teaching language, and aiding those with reading difficulties. Chalkboards and bulletin boards visually display information for teaching. Chalkboards allow for erasing mistakes and pacing demonstrations. Bulletin boards approach, develop and summarize units. E-boards act as digital libraries and data visualization tools to facilitate group discussions and decision making.