In-ear functional near-infrared spectroscopy for cognitive load estimation

An in-ear device (IED) configured to be placed within an ear canal of a user, the IED comprising:

• a first set of functional near-infrared spectroscopy (fNIRS) optodes that are configured to capture first fNIRS signal data representing hemodynamic changes in a brain of the user;
• at least one electroencephalography (EEG) electrode that is disposed on the IED so as to be in contact with an inner surface of the ear canal, and that is configured to capture electrical signals corresponding to brain activity of the user;
• a controller configured to:
• filter the first fNIRS signal data based in part on the electrical signals to generate filtered fNIRS signal data;
• use a machine-learned model to estimate an amount of blood oxygenation change in a superior temporal gyrus of the user based on the filtered fNIRS signal data;
• determine that the estimate of the amount of blood oxygenation change satisfies a threshold condition;
• and
• adjust an audio setting of an audio signal of the IED based on the satisfaction of the threshold condition;
• and
• a speaker configured to present the adjusted audio signal of the IED to the user.

A method comprising:

• capturing first fNIRS signal data with a first set of functional near-infrared spectroscopy (fNIRS) optodes disposed on an in-ear device (IED) configured to be placed within an ear canal of a user, the first fNIRS signal data representing hemodynamic changes in a brain of the user;
• capturing electrical signals corresponding to brain activity of the user;
• filtering the first fNIRS signal data based in part on the electrical signals to generate filtered fNIRS signal data;
• using a machine-learned model to estimate an amount of blood oxygenation change in a superior temporal gyrus of the user based on the filtered fNIRS signal data,
• determining that the estimate of the amount of blood oxygenation change satisfies a threshold condition;
• adjusting an audio setting of an audio signal of the IED based on the satisfaction of the threshold condition;
• and
• presenting the adjusted audio signal of the IED to the user.