Maryanne Amacher made music in which some of the sounds are produced inside the listener’s ears.
The phenomenon is called an otoacoustic emission. When the ear receives certain combinations of frequencies, the nonlinear mechanics of the cochlea can produce additional frequencies. A common distortion product is:
2f₁ − f₂
This sound is not simply another oscillator in the recording. The ear itself contributes to it.
Amacher called these sounds “ear tones” and explored them extensively in Sound Characters (Making the Third Ear) (1999). With carefully constructed combinations of tones, she could create another layer of sound that seemed to originate in or around the listener’s head.
She called this Third Ear Music.
The ear in the signal chain
A normal electronic-music signal chain might be:
oscillator → processing → speaker → ear
Amacher’s work suggests:
oscillator → processing → speaker → ear → new sound
The ear becomes another nonlinear component in the system.
I like thinking about this in modular terms. Instead of adding another oscillator, waveshaper, or feedback path, part of the synthesis happens in the listener.
This also means the finished sound does not entirely exist in the recording. It emerges from the interaction between the electronic signal, speakers, room, and a particular listener’s auditory system.
That makes Amacher’s work interesting beyond the psychoacoustic effect itself. She was not only composing sounds; she was composing the conditions that produce them.
The listener completes the patch.
Listening
The obvious starting point is Sound Characters (Making the Third Ear), particularly “Head Rhythm 1 / Plaything 2.” The embedded clip features Amacher speaking about the problem of recordings — a useful companion to music whose full effect depends on a particular listener, room, and playback setup.
This is something to approach carefully. The effect does not require treating extreme volume as an experiment; prolonged high-frequency or high-level sound can damage hearing.
References
- Sound Characters (Making the Third Ear) — Tzadik, 1999
- “Head Rhythm 1 / Plaything 2” close listening — Music Theory Online