Internal physiological noise from blood flow and heartbeat raises low-frequency thresholds

Evidence

At low frequencies it is assumed that the subject produces his/her own noise as a consequence of the blood supply in the inner ear and of vibrations produced by the heart and muscles. We adapt to this noise because it is always there and therefore we don’t usually hear it, particularly in our normal surroundings. This kind of internal noise is especially strong at low frequencies. At medium and high frequencies there may be noise produced in the neural processing. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1148

Categorization

• XREF: Connects to the physiology of hearing and to noise-masking research; resonates with the ‘silence’ theme books already in the library about how we adapt to always-present sound. — connects to: Internal body noise, dominated by heartbeats and muscles, masks quiet sounds at low frequencies.; Inner-ear blood-flow noise is adapted out because it never stops; Perceptual insensitivity to low-frequency sound masks its physiological impact on the inner ear (+3 more)
• CANDY: We cannot hear very low frequencies partly because our own heartbeat and blood flow mask them — a good cocktail fact.
• corroborated: 2 independent passages support this claim — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1148

Broader Connections

• Internal body noise, dominated by heartbeats and muscles, masks quiet sounds at low frequencies. #corroborates (0.95)
• Inner-ear blood-flow noise is adapted out because it never stops #complicates (0.80)
• The brain amplifies internal noise so total silence cannot be perceived #expands (0.72) — George Michelsen Foy, Zero Decibels, 609
• Perceptual insensitivity to low-frequency sound masks its physiological impact on the inner ear #corroborates (0.70)