Sounds in the median plane are localized to fixed directions based on frequency

Evidence

Another interesting feature is the localization of narrow-band sounds in the median plane. This effect can be illustrated by means of Fig. 15.13. With some simplification, it can be stated that sounds are perceived as coming from a specific direction, irrespective of the location of the sound source. If narrow-band sounds with a centre frequency of 300 Hz or 3 kHz are presented, the sound image is always perceived in front of the subject. Narrow-band sounds centred at 8 kHz are perceived as coming from a location above the head of the subject, even if the sound source is located in front of the subject. Narrow-band sounds centred at lor 10 kHz are perceived to originate behind the head of the subject, again irrespective of the actual location of the sound source. This is an astonishing effect and was attributed by Blauert to the frequency characteristics of the hearing system, and was called “determining frequency bands” . — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1720

Categorization

• DEFINE: Introduces the concept of ‘determining frequency bands’ — narrow-band sounds map to fixed perceived directions in the median plane regardless of true source location.
• CANDY: A fun bar fact: narrow-band tones at 8 kHz are always perceived as coming from above your head regardless of where the sound actually is.
• XREF: connects to: A stationary tone’s frequency alone can shift perceived elevation in the median plane. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1452