Distance Adjustments in Loudness Metering

Visiting Research Student: Leandro da Silva Pires
IoSR Principal Supervisor: Dr Tim Brookes
IoSR Co-Supervisor: Dr Russell Mason
Home Principal Supervisor: Prof Maurílio N Vieira
Home Co-Supervisor: Prof Hani C Yehia
Home Institution: Universidade Federal de Minas Gerais
Visit Supported by: Agência Nacional de Telecomunicações

Start date: 2017
End date: 2018

Project Outline

As part of a larger doctoral project on loudness prediction for immersive audio, the project component conducted at the IoSR aimed to determine the impact of source distance on loudness perception and to suggest how it might be incorporated into loudness prediction systems and meters such as that detailed in Recommendation ITU-R BS.1770. Method-of-adjustment listening tests were conducted in the IoSR's critical listening room and in a more reverberant space, using four programme items replayed from one of five loudspeakers spaced from 0.89 to 4.50 meters from the listener. The listener was tasked with adjusting the replay level of each loudspeaker such that its loudness matched that of each of the others. The results indicated that the ITU-R loudness model might be modified to better account for distance-related loudness variations, and a suitable modification was proposed.