This photograph shows the Rhodes Audiphone in use. The model holds a flexible sheet of vulcanite, adjusted to a convex shape by means of cords, between her teeth. Sound was gathered through the fan area, then traveled via the upper teeth to the inner ear by bone conduction. The cords kept the fan under tension, providing for better vibration. The sound device on the model’s lap is a folding “Dentaphone,” a similar bone conduction hearing device.