Recording technique using two microphones placed in artificial ear shells (dummy head) or the human ear canal to create spatially authentic headphone playback.
Technical Details
Binaural recordings use dummy head microphones with two condenser microphones in synthetic earcups or in-ear microphones placed directly in human ear canals. The head diameter is typically 18 cm, with earcups simulated by anatomically shaped silicone or rubber replicas. The frequency response is usually 20 Hz to 20 kHz with an impedance of 200 ohms. Modern systems like the Neumann KU 100 utilize pre-polarized condenser microphones and integrated 48V phantom power.
History & Development
Clément Ader developed the first binaural system for telephone transmissions of the Paris Opera in 1881. In 1933, Bell Labs constructed the first dummy head for stereo recordings. Deutsche Grammophon produced the first commercial LPs using binaural techniques in 1974. The Neumann KU 80 became the industry standard in the 1970s. Since 2010, digital signal processing has enabled real-time binaural synthesis for VR applications.
Practical Application in Film
"Das Boot" (1981) used binaural recordings for submarine interiors to enhance claustrophobia. Horror productions like "A Quiet Place" (2018) employ the technique for atmospheric forest scenes. VR films such as "Dear Angelica" (2017) utilize binaural 360° recordings for immersive soundscapes. The workflow requires special monitor mixes, as binaural recordings sound unnatural over loudspeakers. Post-production is exclusively done via reference headphones like the Sennheiser HD 650.
Comparison & Alternatives
Binaural technology differs from stereo through head-related transfer functions (HRTF). Ambisonic recordings offer loudspeaker compatibility but lack physiological precision. The Dolby Atmos Binaural Renderer converts multichannel mixes retrospectively but does not achieve the authenticity of true dummy head recordings. For cinema releases, binaural remains a niche technique, while streaming platforms increasingly support binaural formats for mobile playback.