Speaker in the Ear/”Open Fit” Design

Improved user acceptance
Dual places the speaker directly in the ear and the amplifier behind it for improved sound quality. 

Clear, comfortable sound quality
Dual delivers a smoother, less distorted sound than thin tube BTE solutions because it avoids the problem of tube resonance.

Frequency response from Dual compared with a typical "thin tube" solution showing the improved sound quality by placing the receiver in the ear canal.

“Open fit” Design

Dual’s vented earpiece design lets your ear “breathe” for better and more long-lasting wearing comfort. Sounds enter your ear directly through the dome, and also vial the Dual Speaker.  This gives you the most ideal access to the sounds in your world.