Low-frequency Bounce occurs even with the ear canal left open

Evidence

Here, we recorded SOAEs in the open meatus using an ER10C probe microphone fitted to the meatus via an about 8 cm silicon tube (2.8 mm outer diameter) which did not block the meatus. The tip of the tube was positioned about 10 mm in front of the tympanum. LF exposure was provided by two powerful custom-made subwoofers. Subjects lay on a deck chair in a long basement corridor at a point where standing waves in the corridor maximised the sound level at 30 Hz. LF exposure was 118 dB SPL for 90 s. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3703

Both ears of 45 young, normal-hearing subjects were screened for SOAEs. 33 subjects showed at least one SOAE in one ear. Overall we could record in the open meatus about 52 % of those SOAEs detectable in a sound-attenuated room and a closed-ear recording technique. The remaining 48 % were not significantly above the much higher noise floor of the free-field, open-meatus measurement. … Exemplary measurements of both permanent and transient SOAEs are shown in Fig. 3c and d in the same format as Fig. 2 . Indeed many of those 48 % SOAEs that had been initially identified in the closed-meatus measurements, but could no longer be detected in the open meatus, appeared directly after the LF exposure for a short time period, before falling again below the noise floor (Fig. 3d ). These data clearly show that Bouncing of SOAEs can indeed be elicited by free-field exposure to LF sound sources of natural or anthropogenic origin. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3729

Categorization

Category: Factual Claims

• XREF: Rules out middle-ear impedance or closed-canal artifacts as the Bounce’s cause — so the effect persists under natural listening conditions — a controls-mechanics point echoing the earlier project’s method-heavy ethos.

Related

• SOAE Bouncing occurs in open-ear listening to real-world low-frequency sound sources. (similarity 0.92)
• Real-world low-frequency noise can trigger the Bounce (similarity 0.89)
• Free-field low-frequency sound causes SOAE bouncing without ear canal occlusion (similarity 0.89)
• SOAE bouncing occurs in an open meatus, not only in a sealed ear canal (similarity 0.88)
• Free-field low-frequency sound from natural or man-made sources elicits SOAE bouncing (similarity 0.87)
• SOAE bouncing is not caused by the probe blocking the ear canal (similarity 0.87)
• Low-frequency exposure temporarily activates new otoacoustic emissions that were previously absent in most ears. (similarity 0.85)
• SOAE bouncing is not caused by middle-ear impedance changes (similarity 0.83)
• Intense low-frequency sound alters inner ear function even though we barely hear it (similarity 0.81)
• Low-frequency stimulation can reveal latent otoacoustic emissions invisible before exposure (similarity 0.81)
• Low-frequency sound can awaken silent inner ears to emit spontaneous tones (similarity 0.81)
• Low-frequency exposure measurably alters cochlear amplifier gain via outer hair cell activity (similarity 0.80)
• Low-frequency sound’s after-effects arise from calcium homeostasis in outer hair cells (similarity 0.80)
• Low-frequency stimulation can make previously undetectable spontaneous emissions emerge transiently (similarity 0.79)
• Low-frequency sound exposure triggers long-lasting damped oscillations in spontaneous otoacoustic emissions. (similarity 0.79)

Broader Connections

• SOAE bouncing is not caused by middle-ear impedance changes #corroborates (0.85) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3729
• SOAE Bouncing occurs in open-ear listening to real-world low-frequency sound sources. #corroborates (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3711
• Real-world low-frequency noise can trigger the Bounce #corroborates (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3703
• The ear becomes less nonlinear as sound levels rise #qualifies (0.70) — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1561