In modern cellular phones / smart phones, various algorithms are applied to enhance speech from nearby talkers and to reduce other sounds. From a forensic perspective, the background sounds are as valuable as the speech. This paper focuses on the evaluation of a smartphone"s ability to pickup background sounds. Initiated by casework, the question is raised whether or not analyses of the background sound provide any valid information. An iPhone 7 is examined. Sensitivity to background sounds and directivity is measured. Also, a balloon pop-test is applied. The conclusion is that the level of broadband background sounds must exceed approximately 70 dB(A) to be transmitted by the iPhone 7. The balloon popping test was carried out with five different smartphones.

Author: Brixen, Eddy B.
Affiliation: EBB-consult, Smorum, Denmark
AES Conference: 2019 AES International Conference on Audio Forensics (June 2019)
Paper Number: 28
Publication Date: June 8, 2019 Import into BibTeX
Permalink: https://www.aes.org/e-lib/browse.cfm?elib=20478

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