Video: ‘Enhancing forensic audio’, a presentation at ISCA SPSC

Helen Fraser delivered a webinar to the International Speech Communication Association’s Special Interest Group on Security and Privacy in Speech Communication on 12 June. We had a very engaged and responsive audience, some of whom will be taking the issues forward via ongoing discussion – let us know if you would like to be involved.

Please find the abstract and video below.

Thanks to Karla Pizzi for hosting and recording, and special thanks to Candy Mawalim for inviting and organising.

Enhancing forensic audio: What works, what doesn’t – and how can we know?

Recorded speech used as evidence in criminal trials is often of poor quality, making it hard for the court to understand the content. ‘Enhancing’ aims to improve the audio, via techniques such as noise reduction, gain control, or spectral subtraction (Maher, 2018). Results are usually evaluated by measuring the acoustic effects of the enhancing processes, and observing whether the audio sounds clearer, without unwanted artefacts. But what does it mean to say the audio ‘sounds clearer’? Can we be sure that what sounds clear to the scientist will also sound clear to the judge and jury? Is it possible they might hear it ‘clearly’ but wrongly? This webinar gives new insights on these questions (Fraser 2019 gives a quick impression), and seeks assistance from the signal processing community in ensuring that the courts gain a reliable interpretation of poor-quality forensic audio.