Comment on “The cochlear amplifier as a standing wave: ‘Squirting’ waves between rows of outer hair cells?” [J. Acoust. Soc. Am. 116, 1016–1024 (2004)]

Bell and Fletcher [J. Acoust. Soc. Am. 116, 1016–1024 (2004)] proposed that one of the functions of activity of the outer hair cells (OHCs) might be a fluid-pumping action generating lateral fluid flow in the gap between the reticular membrane and the tectorial membrane and they supplied mathematical and descriptive justification for their theory which drew heavily upon the postulation (Gold, 1948) of the need for an active mechanism in the mammalian cochlea. In the 1970s there had been considerable speculation about how the inner hair cell (IHC) stereocilia are stimulated, whether they are stimulated in proportion to basilar membrane displacement or velocity or both, and whether the velocity dependence is due to subtectorial fluid flow. In 1977 experiments were conducted to investigate the possibility of subtectorial fluid flows using a dye as tracer. The work was not reported because it had been conducted at a time when visual observation of cochlear function had fallen out of favor in comparison with the more sensitive techniques thought necessary to observe submicroscopic phenomena, and secondly because it yielded a negative result. The essential details of those experiments are reported here to note for the record the extent to which this elaborate idea has already been tested.