Audiovisual integration capacity modulates as a function of illusory visual contours, visual display circumference, and sound type

Research into the capacity of audiovisual integration has previously assessed whether capacity is strictly limited to a single item, or whether it can exceed one item under certain environmental conditions. More recently, investigations have turned to examining the effects of various stimulus factors on capacity. Across two experiments, we looked at a number of factors that were expected to play a modulatory role on capacity. Experiment 1 deployed a manipulation of illusory polygons, revealing an increase in audiovisual capacity, even in an absence of visual connections. This demonstrates that exceeding the capacity of 1 does not only represent a functional increase in the binding of a singular, complex visual object, but that it can also represent binding of multiple simpler objects. Findings also support the hypothesis that capacity modulates quantitatively, but not qualitatively, with respect to speed of presentation. Experiment 2 examined the effects of different sound types (sine tones or white noise) and of different spatial visual field sizes on the capacity of audiovisual integration. The results indicated that capacity is maximized when stimuli are presented in a smaller circle (7.5°) if alongside a sine tone, and when presented in a larger circle (18.5°) alongside a white noise. These results suggest that audiovisual integration capacity is dependent on the combination of sound type and visual spatial field size. The combination of these results reveal additional phenomenological features of the capacity of audiovisual integration, and provides impetus for further research into applications of the findings.

Electronic Inspirations

Cold War electronic music—made with sine tone and white-noise generators, filters, and magnetic tape—was the driving force behind the evolution of both electronic and acoustic music in the second half of the twentieth century. Electronic music blossomed at the Westdeutscher Rundfunk (WDR [West German Radio]) in Cologne in the 1950s, when technologies were plentiful and the need for cultural healing was great. Building an electronic studio, West Germany confronted the decimation of the “Zero Hour” and began to rebuild its cultural prowess. The studio’s greatest asset was its laboratory culture, where composers worked under a paradigm of invisible collaboration with technicians, scientists, performers, intellectuals, and the machines themselves. Composers and their invisible collaborators repurposed military machinery in studio spaces that were formerly fascist broadcasting propaganda centers. Composers of Cold War electronic music reappropriated information theory and experimental phonetics, creating aesthetic applications from military discourses. In performing such reclamations, electronic music optimistically signaled cultural growth and progress, even as it also sonified technophobic anxieties. Electronic music—a synthesis of technological, scientific, and aesthetic discourses—was the ultimate Cold War innovation, and its impacts reverberate today.

Duifhuis pitch: neuromagnetic representation and auditory modeling

When a high harmonic is removed from a cosine-phase harmonic complex, we hear a sine tone pop out of the perception; the sine tone has the pitch of the high harmonic, while the tone complex has the pitch of its fundamental frequency, f0. This phenomenon is commonly referred to as Duifhuis Pitch (DP). This paper describes, for the first time, the cortical representation of DP observed with magnetoencephalography. In experiment 1, conditions that produce the perception of a DP were observed to elicit a classic onset response in auditory cortex (P1m, N1m, P2m), and an increment in the sustained field (SF) established in response to the tone complex. Experiment 2 examined the effect of the phase spectrum of the complex tone on the DP activity: Schroeder-phase negative waves elicited a transient DP complex with a similar shape to that observed with cosine-phase waves but with much longer latencies. Following the transient DP activity, the responses of the negative and positive Schroeder-phase waves converged, and the increment in the SF slowly died away. In the absence of DP, the two Schroeder-phase conditions with low peak factors both produced larger SFs than cosine-phase waves with large peak factors. A model of the auditory periphery that includes coupling between adjacent frequency channels is used to explain the early neuromagnetic activity observed in auditory cortex.

Resonator properties of paranasal sinuses: preliminary results of an anatomical study

Background: The contribution of the nasal and paranasal cavities to vocal tract resonator properties is unclear as are voice effects of sinus surgery. Here we investigate resonance phenomena of paranasal sinuses with and without selective occlusion of the middle meatus and maxillary ostium in a cadaver. Methodology: Nasal and paranasal cavities of a Thiel-embalmed cadaver were excited by sine-tone sweeps from an earphone in the epipharynx. The response was picked up by a microphone at the nostrils. Different conditions with blocked and unblocked middle meatus were tested. Additionally, infundibulotomy was performed allowing direct access to and selective occlusion of the maxillary ostium. Results: Responses showed high reproducibility. Minor effects appeared after removal of meatal occlusion. A marked low frequency dip was detected after removal of occlusion of maxillary ostium following infundibulotomy. Conclusion: Reproducible frequency responses of nasal tract can be derived from cadaver measurements. Marked acoustic effects of the maxillary sinus appeared only after direct exposure of the maxillary ostium following infundibulotomy.