Changing the shape of the outer ear using small in-ear molds degrades sound localization performance consistent with the distortion of monaural spectral cues to location. It has been shown recently that adult listeners re-calibrate to these new spectral cues for locations both inside and outside the visual field. This raises the question as to the teacher signal for this remarkable functional plasticity. Furthermore, large individual differences in the extent and rate of accommodation suggests a number of factors may be driving this process. A training paradigm exploiting multi-modal and sensory-motor feedback during accommodation was examined to determine whether it might accelerate this process. So as to standardize the modification of the spectral cues, molds filling 40% of the volume of each outer ear were custom made for each subject. Daily training sessions for about an hour, involving repetitive auditory stimuli and exploratory behavior by the subject, significantly improved the extent of accommodation measured by both front-back confusions and polar angle localization errors, with some improvement in the rate of accommodation demonstrated by front-back confusion errors. This work has implications for both the process by which a coherent representation of auditory space is maintained and for accommodative training for hearing aid wearers.

Background: Placenta praevia is characterised by an inferior placental margin that overlies or falls within 20 mm of the endocervical os. It remains a common cause of antepartum haemorrhage and is associated with adverse maternal and neonatal outcomes. Aims: We aimed to determine the association between antepartum and postpartum haemorrhage and adverse outcomes in cases of placenta praevia. Materials and Methods: The study population included women diagnosed with placenta praevia, who delivered between 1 April 2007 and 30 April 2017. The endpoints of interest included blood transfusion, emergency caesarean section, peripartum hysterectomy and admission to intensive care. Results: There were 513 cases of placenta praevia, of which 67.3% delivered at term. Antepartum haemorrhage was associated with an increased risk of blood transfusion (relative risk (RR) 3.29; 95% CI 2.04-5.32), emergency caesarean section (RR 1.38; 95% CI 1.18-1.62) and preterm delivery, after 32 weeks gestation (RR 4.21; 95% CI 2.77-6.38). Postpartum haemorrhage more than doubled the risk of blood transfusion (RR 9.08 95% CI 5-16.44) and admission to the intensive care unit (RR 10.44; 95% CI 2.34-46.59), as well as increased the risk of peripartum hysterectomy (1.4%). We also described the management of 12 cases of placenta praevia (2.3% of the study population) delivered vaginally. Conclusions: Antepartum and postpartum haemorrhage in cases of placenta praevia are predictors of several adverse outcomes. However, the high rate of term deliveries reaffirms the current practice of expectant management.

The capacity of healthy adult listeners to accommodate to altered spectral cues to the source locations of broadband sounds has now been well documented. In recent years we have demonstrated that the degree and speed of accommodation are improved by using an integrated sensory-motor training protocol under anechoic conditions. Here we demonstrate that the learning which underpins the localization performance gains during the accommodation process using anechoic broadband training stimuli generalize to environmentally relevant scenarios. As previously, alterations to monaural spectral cues were produced by fitting participants with custom-made outer ear molds, worn during waking hours. Following acute degradations in localization performance, participants then underwent daily sensory-motor training to improve localization accuracy using broadband noise stimuli over ten days. Participants not only demonstrated post-training improvements in localization accuracy for broadband noises presented in the same set of positions used during training, but also for stimuli presented in untrained locations, for monosyllabic speech sounds, and for stimuli presented in reverberant conditions. These findings shed further light on the neuroplastic capacity of healthy listeners, and represent the next step in the development of training programs for users of assistive listening devices which degrade localization acuity by distorting or bypassing monaural cues.