Synopsis: Striking the right tone

A better understanding of human pitch perception has been achieved with an electronic analog of the cochlea.

Despite efforts by some of the most famous names in physics such as Ohm and von Helmholtz, human perception of acoustic pitch remains an unsolved puzzle. The problem is especially complex because a well-characterizable physical stimulus (sound) is detected by a heretofore poorly understood psychophysiological signal receiver (the ear). The cochlea is the ear’s signal transducer, and many models of it seem to work but then fail empirically, for example, in the case of the missing fundamental: even if the lowest frequency is removed from a sound, humans still perceive the pitch as the lowest frequency from the higher harmonics.

In Physical Review Letters, Stefan Martignoli and Ruedi Stoop of the University of Zurich and the Swiss Federal Institute of Technology, Zurich, Switzerland, report their use of an electronic cochlea to study the problem of perceived pitch. Cochlear models are often tested by applying different shifts to the pitch of the stimulus and then comparing the response with actual psychoacoustic measurements. Martignoli and Stoop follow the details of such signals through their circuit and detect the changes at each step along the path. They find that the pitch-shifting response that humans perceive can be explained as the result of local nonlinearities in the cochlea itself, rather than effects of higher-level neural processing in the brain. – David Voss


Features

More Features »

Announcements

More Announcements »

Subject Areas

Biological Physics

Previous Synopsis

Next Synopsis

Nuclear Physics

The limits of a closed shell

Read More »

Related Articles

Focus: How 1000 Bacterial Species Can Coexist
Biological Physics

Focus: How 1000 Bacterial Species Can Coexist

The surprising stability of large and diverse bacterial communities can be explained by a model that emphasizes the microbes’ food requirements. Read More »

Synopsis: Connecting Noisy Single-Cell Dynamics to Smooth Population Growth
Biological Physics

Synopsis: Connecting Noisy Single-Cell Dynamics to Smooth Population Growth

A new theoretical framework connects the exponential growth of a cell population to the stochastic replication of individual cells within the population. Read More »

Viewpoint: Brain Motion Under Impact
Nonlinear Dynamics

Viewpoint: Brain Motion Under Impact

A numerical study suggests that head impacts primarily induce a few low-frequency, damped modes of vibration in brain tissue, a finding that could inform the design of sports helmets. Read More »

More Articles