We simulated the effect of several automatic gain control (AGC) and AGC-like systems and head movement on the output levels, and resulting interaural level differences (ILDs) produced by bilateral cochlear-implant (CI) processors. The simulated AGC systems included unlinked AGCs with a range of parameter settings, linked AGCs, and two proprietary multi-channel systems used in contemporary CIs. The results show that over the range of values used clinically, the parameters that most strongly affect dynamic ILDs are the release time and compression ratio. Linking AGCs preserves ILDs at the expense of monaural level changes and, possibly, comfortable listening level. Multichannel AGCs can whiten output spectra, and/or distort the dynamic changes in ILD that occur during and after head movement. We propose that an unlinked compressor with a ratio of approximately 3:1 and a release time of 300-500 ms can preserve the shape of dynamic ILDs, without causing large spectral distortions or sacrificing listening comfort.

Introduction. Decentering describes the ability to voluntarily adopt an objective self-perspective from which to notice internal, typically distressing, stressors (e.g. difficult thoughts, memories, and feelings). The reinforcement of this skill may be an active ingredient through which different psychological interventions accrue reductions in anxiety and/or depression. However, it is unclear if decentering can be selectively trained at a young age and if this might reduce psychological distress. The aim of the current trial is to address this research gap. Methods and analysis. Adolescents, recruited from partnering schools in the UK and the EU (n = 48 per group, age range = 16-19 years), will be randomised to complete of five-weeks of decentering training, or form an active control group that will take part in in light physical exercise and cognitive training. The co-primary training outcomes include a self-reported decentering inventory (i.e. the Experiences Questionnaire) and the momentary use of decentering in response to psychological stressors, using experience sampling. The secondary mental health outcomes will include self-reported inventories of depression and anxiety symptoms, as well as psychological wellbeing. The initial statistical analysis will use mixed-model analysis of variance (ANOVA) to estimate the effect of training condition on self-rated inventories across three timepoints: baseline, mid-intervention and post-intervention. Additionally, experience sampling data will be initially interrogated using hierarchical linear models. Ethics and dissemination. This study was approved by the Cambridge Psychology Research Ethics Committee, University of Cambridge (PRE.2019.109). Findings will be disseminated through typical academic routes including poster/paper presentations at (intern)-national conferences, academic institutes and through publication in peer-reviewed journals.