Ключевые слова: amateur, antenna, audio, background, black, broadcast, business, button, closeup, communication, communications, conference, device, digital, electronic, electronics, entertainment, equipment, event, frequency, lecture, mic, microphone, music, panel, presentation, professional, radio, receiver, seminar, set, sign, signal, sound, speak, speaker, spectrum, speech, stage, station, studio, talk, technology, ted, training, transceiver, transmitter, voice, wave, wireless,