Hearing loss is a rapidly expanding health concern, which has a devastating social impact, reducing our ability to have a conversation in noisy environments, and consigning the deaf to social isolation. Hearing loss can have other debilitating consequences, as sufferers begin to hear phantom sounds; these are loud, distracting and imaginary sounds, known as tinnitus. Although tinnitus is typically preceded by hearing loss, it is usually not generated in the ear, but is ‘created’ by the brain. The general consensus is that tinnitus results from abnormal excitability in the central auditory system, but neither the location of the problem nor the exact plasticity processes underlying tinnitus are well understood.
The LISTEN (Liaison In Scientific Training for European auditory Neuroscience) training network consisted of European auditory neuroscientists working with several European companies to improve hearing aids (including cochlear implants) and pharmacological treatments for tinnitus and hearing loss.
The overall objectives for LISTEN were:
1) To elucidate how the auditory system encodes complex sounds, both in normal and compromised hearing.
2) To study the underlying mechanisms of tinnitus, and test possible pharmacological treatments.
3) To train 10 ESRs to acquire technical skills and broader knowledge necessary in modern neuroscience research, while also learning to relate and translate their work for industrial and clinical applications.
The LISTEN project has led to new, fundamental insights into the question how the auditory system deals with the large range of sound intensities and sound frequencies it has to encode, how attention can modulate the encoding of the location of sounds, or the way the brain detects novel sounds. Moreover, mechanisms underlying different forms of hearing loss were elucidated, and some of the functional changes in the brain that occur in tinnitus were studied in detail. Finally, the LISTEN project has successfully trained 10 ESRs as auditory neuroscientists, which either have defended their thesis or are preparing to do so this year.