Philip M. Rose

Bulk acoustic absorber panels for use in high‐speed gas flow environments

A sandwich type acoustical absorbing panel for use adjacent high speed gas flow areas in and around the engines of high speed aircraft. The panel comprises a pan type base having an imperforate base member and upstanding sides and end walls, an acoustic absorbing medium is disposed within the pan type base, a rigid perforated plate is secured to the distal surfaces of the upstanding sides and end walls for enclosing the acoustic absorbing medium and a sheet of fine woven mesh is secured to the outer surface of the rigid perforated plate. The outer positioned fine woven mesh enhances acoustic properties of the panel and substantially prevents entry of water, dust, chemicals and similar foreign matter from penetrating into the panel structure and reduces the aerodynamic drag loss normally encountered by high speed gas flows across perforated material, such as, that normally used for the outer surface of acoustic panels.

Measuring reliability in forensic voice comparison.

Recently there has been a great deal of concern in forensic science about validity and reliability (accuracy and precision). The log‐likelihood‐ratio cost (Cllr), developed for automatic speaker recognition, is increasingly applied as a standard measure of accuracy in forensic voice comparison, but so far there has been little work on developing a metric of precision within this field. Because voice data can have a large amount of intrinsic variation at the source, and likelihood ratios are typically calculated using a single suspect recording and a single offender recording, assessing the precision of a forensic‐voice‐comparison system is extremely important. This presentation discusses the importance of measuring precision and describes two procedures, one parametric and one non‐parametric, for calculating 95% credible intervals for the likelihood ratios resulting from running tests of forensic‐voice‐comparison systems (in which some comparisons are known to be same‐speaker comparisons and others are kn...