Listeners perceptually normalize their own idiosyncratic HRTFs from birth

Evidence

HRTFs are different for every individual, which means that as individuals we have adapted to—normalized—our personal HRTFs. We all are able to recognize the timbres of familiar sounds, even though the same sounds do not reach all of our eardrums. In sound reproduction we recognize the uncolored sound from loudspeakers having flat, neutral frequency responses, while listening through our hearing system HRTFs that are anything but flat. We start auditory adaptation from birth, it seems. An interesting question is: how flexible is that adaptation? — Toole, Floyd E, Sound reproduction- the acoustics and…, 292

Categorization

• DEFINE: Clarifies HRTF normalization: the brain treats its own ear-specific transfer functions as uncolored baseline, regardless of how non-flat they physically are.
• QUESTION: The chapter ends on ‘how flexible is that adaptation?’ — the plasticity limits of HRTF normalization remain an open research question worth chasing.