Effect of Blast Injury on Auditory Localization in Military Service Members.

OBJECTIVES: Among the many advantages of binaural hearing are the abilities to localize sounds in space and to attend to one sound in the presence of many sounds. Binaural hearing provides benefits for all listeners, but it may be especially critical for military personnel who must maintain situational awareness in complex tactical environments with multiple speech and noise sources. There is concern that Military Service Members who have been exposed to one or more high-intensity blasts during their tour of duty may have difficulty with binaural and spatial ability due to degradation in auditory and cognitive processes. The primary objective of this study was to assess the ability of blast-exposed Military Service Members to localize speech sounds in quiet and in multisource environments with one or two competing talkers. DESIGN: Participants were presented with one, two, or three topic-related (e.g., sports, food, travel) sentences under headphones and required to attend to, and then locate the source of, the sentence pertaining to a prespecified target topic within a virtual space. The listener's head position was monitored by a head-mounted tracking device that continuously updated the apparent spatial location of the target and competing speech sounds as the subject turned within the virtual space. Measurements of auditory localization ability included mean absolute error in locating the source of the target sentence, the time it took to locate the target sentence within 30 degrees, target/competitor confusion errors, response time, and cumulative head motion. Twenty-one blast-exposed Active-Duty or Veteran Military Service Members (blast-exposed group) and 33 non-blast-exposed Service Members and beneficiaries (control group) were evaluated. RESULTS: In general, the blast-exposed group performed as well as the control group if the task involved localizing the source of a single speech target. However, if the task involved two or three simultaneous talkers, localization ability was compromised for some participants in the blast-exposed group. Blast-exposed participants were less accurate in their localization responses and required more exploratory head movements to find the location of the target talker. CONCLUSIONS: Results suggest that blast-exposed participants have more difficulty than non-blast-exposed participants in localizing sounds in complex acoustic environments. This apparent deficit in spatial hearing ability highlights the need to develop new diagnostic tests using complex listening tasks that involve multiple sound sources that require speech segregation and comprehension.

AuD-degree holders in tenure-track positions: survey of program chairpersons and AuD-degree holders.

BACKGROUND: The doctor of audiology (AuD) degree is now the entry-level degree for the profession of audiology. Typically, AuD programs train professionals for clinical careers, while those offering PhDs educate students for university teaching and research positions. Some in the communication sciences and disorders have predicted that there could be a shortage of PhDs in academic institutions over the next decade as senior faculty members with PhDs retire, AuD programs expand, and likely fewer students complete PhD degrees or elect to pursue careers in academia. If a PhD shortage becomes a reality, then one solution might be to include AuDs as candidates for vacant academic tenure-track positions. PURPOSE: To survey AuD-degree holders' (AuDs') and program chairpersons' (chairs') views about AuDs in academic tenure-track positions. RESEARCH DESIGN: National Internet survey Data Collection and Analysis: Two questionnaires were designed for this study. One was e-mailed to 1575 "AuDs in general" (randomly sampled from the American Academy of Audiology Membership Directory) and 132 "AuDs in academia." The other was e-mailed to 64 chairs from programs offering the AuD. The two surveys included similar questions so that comparisons could be made across groups. Potential respondents were e-mailed an informational letter inviting them to participate by completing a survey on SurveyMonkey within a 2 wk period in March and April 2010. This process resulted in three data sets: (1) AuDs in general, (2) AuDs in academia, and (3) program chairs. RESULTS: Return rates were 25, 26, and 45% for the three sampling methods for recruiting AuDs in general, AuDs in academia, and program chairs, respectively. Of the respondents, few AuDs held academic tenure-track positions or had achieved rank and tenure success in them. Those AuDs in academia usually had to meet the same or similarly rigorous criteria (with heavier emphasis on teaching than on research) for advancement as did PhD faculty. Overall, AuDs tended to believe that AuDs could be appointed to and succeed at tenure-track positions; chairs reported that such appointments were not permitted in most programs, did not personally believe that AuDs should hold these positions, and felt that AuDs would have more difficulty than PhDs in achieving success in them. Obstacles to AuDs' success in tenure-track positions reported by all three groups included lack of research skills and mentors, biases from faculty within and outside of audiology departments, and poorer pay than could be earned in the private sector. CONCLUSIONS: Considerable variability existed in the types of and titles for faculty positions held by AuDs in academia. Few AuDs were employed in tenure-track positions. Contrary to many of the chairs' responses, most AuDs felt they would be successful in such positions. Many of the AuDs suggested that universities with AuD programs should add more research and mentorship opportunities and tenure tracks for clinicians. Most respondents believed there is a need for both AuDs and PhDs in academic programs. These findings should be of interest to AuDs, chairs, and other stakeholders in academia, and the survey responses identified some areas warranting future investigation.