Conversation tube dating from 1890,England. This is an assisted listening device; the speaker speaks into the funnel-shaped end and the sound waves pass along the conducting tube made of cloth covered rubber. The sound waves are amplified as they travel along the tube to the earpiece which is placed into the listener's ear canal. The speaking tube and earpiece are made from ebonite | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library |
Bildgröße: | 4881 px × 3581 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |