Our Technology

Design Philosophy

The most important attributes for noise-cancelling earphones are comfort, noise-cancellation effectiveness and audio reproduction quality, and Incus has developed its technology to satisfy all of these criteria.

• Open Acoustic Structure

  Some earphone manufacturers use a “closed” type of acoustic design because of the difficulties in achieving active noise-cancellation above 1 kHz. With this approach, the earphone is made to be a sealed unit and behaves as an ear-plug, blocking the ear canal. This can be uncomfortable for the user, and can interfere with the user’s spatial hearing abilities. In contrast to this, Incus technology incorporates a ventilation channel between the ear-canal and the external air. This ensures user-comfort, and also allows relatively natural spatial hearing when the ANC is muted.

• User-Adjust

  Incus technology includes a digital “user-adjust” control option, which can compensate for the small natural physiological variations in the size and shape of people’s ears and ear-canals, in order to provide perfect, optimized ANC for every individual. The user’s preferred setting is then stored and used as the default.

• Low-power

  A long battery life is essential for all mobile devices, and so the ANC signal-processing must draw minimal current from its own battery or, if externally powered, from its host. The Incus ANC earphones provide more than 60 hours of use from a single AAA cell.

• Low-frequency performance at high sound-pressure levels

  Many noisy travel environments, such as underground trains, feature very high sound-pressure levels at very low frequencies, and it is quite demanding to generate corresponding cancellation signals. Incus acoustics and signal-processing are designed to continue work in this extreme environment, where many other systems will produce uncomfortable audio artefacts.

Engineering

Incus technology is underpinned by the extensive use of electroacoustic mathematical modelling to ensure that the entire signal-processing chain is optimised. Everything from the internal JFET buffer transistor in the electret microphone to the acoustic structure of the earphone has been characterized and designed to work together in harmony.

Manufacturing Technology

The revolutionary Incus “Intelligent Acoustics” technology makes the high-volume, mass-manufacture of ANC earphones possible for the first time.

Every ANC earphone incorporates a microspeaker and a miniature microphone, neither of which can be manufactured with precisely defined sensitivity values, which vary typically by ±3 dB. However, effective ANC requires the control of signals to less than 0.9 dB. Consequently, it is necessary, at present, for manual adjustment on the production line to “trim” the individual signal levels using an acoustic noise-source and an artificial-ear simulator.

Additional problems arise in the specific choice of micro-speaker and microphone to be used by a potential manufacturer, because many are unsuitable owing to their frequency response characteristics.

A further problem is caused by the acoustic design of the spaces and cavities around the microspeaker. Every time a new earphone model is designed, the acoustic properties are new, and this leads to a slow design cycle when the performance of each new model is tuned and optimised, prior to the final external Industrial Design (ID).

The proprietary Incus “Intelligent Acoustics” technology overcomes these problems using the Incus “flash” calibration technology to automate the calibration stage.

The Incus design incorporates an optimised microspeaker and microphone, and an accurate acoustic design with an integral acoustic coupling impedance: all of the critical components required for effective ANC performance. The Incus design incorporates a memory element bearing calibration and other data. This “intelligent acoustic” design enables rapid electronic “flash” calibration, thus eliminating the need for time-consuming manual calibration.

Using the Incus design allows OEMs to change the external ID of the ear-phones without changing any of the systems acoustics, thus enabling rapid design times for differentiated product designs.