The Design of a Personal Audio Superdirective Array in a Room

When a directional sound radiator is placed inside a reverberant environment, its directional characteristics are reduced, due to the uniform distribution of reverberant pressure all around the volume. The only way of achieving good directional characteristics in a reverberant environment is to minimise the power that is radiated into the reverberant field. This paper covers the design stage of a personal audio device which is intended to work as an aid for the hearing impaired, needing a large directive index. The simulation of the array's performance into a reverberant field allows its performance to be estimated at the design stage. The performance of the device is also simulated in terms of Speech Transmission Index (STI), and the array design is optimised to maximise speech intelligibility.