A Front-Back Confusion Metric in Horizontal Sound Localization: The FBC Score

Abstract

In sound localization experiments, currently used metrics for frontback confusion (FBC) analysis weight the occurring FBCs equally, regardless of their deviation from the cone of confusion. To overcome this limitation, we introduce the FBC Score. A sound localization experiment in the horizontal plane with 12 bilaterally implanted cochlear implants (CI) users and 12 normal hearing subjects was performed to validate the method with real data. The overall FBC Rate of the CI users was twice as high as the FBC Score. For the control group, the FBC Rate was 4 times higher than the FBC Score. The results indicate that the FBC Rate is inflated by FBCs that show a considerable deviation from the corresponding value on the cone of confusion. CCS CONCEPTS • Human-centered computing → Laboratory experiments; Virtual reality.

Verstehen im Störschall mit räumlich getrennten Signalquellen und Richtungshören mit Sprachstimuli

“…Für das Set-up des Vollkreises wurde am Studienzentrum Kiel die FBC-Rate erhoben, welche die Rate an Vorne-hinten-Verwechslungen unter Berücksichtigung aller Stimuluspräsentationen darstellt. Dabei beschreibt die Vorne-hinten-Verwechslung eine Antwort, die die interaurale Achse überschreitet [ 11 ].…”

Multichannel acoustic source and image dataset for the cocktail party effect in hearing aid and implant users

“…the participant's head or a head and torso simulator (Brüel & Kjaer, Type 4128, Naerum, Denmark) at ear level (see Fig. 1d) 45,46 . For our measurement setup and the presented stimuli, the critical distance is approximately 1.9 m. The directivity index was chosen with a value of Q = 3 corresponding to the spectral power density of human speech or babble noise 47 and the directivity index diagram shown in the Control 1 Pro (JBL) loudspeaker data sheet.…”

Effects of temporal fine structure preservation on spatial hearing in bilateral cochlear implant users

“…The absolute localization accuracy was determined by the root mean square error (RMSE LOC , in degree angle) for all stimuli (N ¼ 36) [e.g., Hartmann and Rakerd (1989)]. To evaluate the influence of front-back confusions (FBCs) on the localization performance, we used the FBC Rate, which is defined as the proportion of responses crossing the interaural axis with respect to the stimulus position [e.g., Carlile et al (1997)] and the FBC score which refines the FBC rate by weighting the abovementioned responses deviation from the corresponding position on the cone of confusion (Fischer et al, 2020a). The interaural axis is defined by a straight line passing through the left ear (270 azimuth) and the right ear (90 azimuth).…”