Participate | SoundBrain Laboratory

Current Opportunities to Participate in SoundBrain Lab Studies

The following SoundBrain Lab studies are currently recruiting participants and pay for your time. Please find the descriptions and requirements for each study below. Please email soundbrainlab@northwestern.edu for further questions or specific study inquiries (it helps if you include the study title in the email subject!). We thank you for your consideration to participate in research!

1. Developing a Neural Snapshot of Speech Processing (Neura-Speech)

The SoundBrain Lab is seeking participants for a research study that aims to explore how our brains encode and differentiate speech sounds (such as “b” vs. “p”), and how the ability to do so interacts with the ease (or lack thereof) at which we can understand speech in different environments, like in background noise.

As we get older, many people notice that following conversations—especially in noisy places—can become more challenging. Recent research by the SoundBrain Lab (Guo et al., 2025) found that in middle-aged adults, the brain’s responses to different speech sounds are less distinct than in younger adults. In other words, the brain’s “signal” for speech becomes a bit fuzzier with age, which might make it harder to tell sounds apart. We aim to build on these findings in our Neura-Speech study.

Watch this brief video of our research assistant professor, Dr. Jacie McHaney, explaining the premise of this study:

You may be eligible if:

You are between 18-70 years old and a native English speaker.

You have normal hearing (no known hearing loss)

You have no history of ear surgery/disorders or neurological/neurodevelopmental disorders.

You can travel to the Northwestern Evanston campus.

Participation may include the following:

Hearing assessment

Listening tasks

Measures of pupil dilation

Measures of brain activity to sounds using electroencephalography (EEG)

All measures are non-invasive. Participation occurs over 1 visit lasting up to 3.5 hours. Participants will be compensated for their time and effort at an hourly rate of $20/hour.

If you are interested, please complete this brief eligibility survey.

If you have any questions, feel free to email us at soundbrainlab@northwestern.edu. A study team member will get back to you shortly.

Principal Investigator: Bharath Chandrasekaran, PhD

Study Title: Neural Snapshot of Speech Processing

IRB: STU00222157

This study is supported through the Ryan Family Research Acceleration Fund; read more about our Neura-Speech project here.

What to Expect When Participating in SoundBrain Lab Studies

Described below are some measures the SoundBrain Lab uses to answer our many research questions. Each study conducted in the SoundBrain Lab is unique and may consist of one, some, or all of these measures (and more)!

Electroencephalography (EEG)

Electroencephalography (EEG) is a non-invasive method of measuring brain activity that can be used in research to study a variety of topics, such as how our brains process speech. In the SoundBrain Lab, we measure EEG while sounds, like the speech syllable “da” or the audiobook “Alice’s Adventures in Wonderland“, are played to each ear.

Depending on the goals of the study, the SoundBrain Lab measures EEG using two different set-ups:

1. With five electrodes (sensors) placed on your head; specifically, these electrodes are placed behind each ear, on the forehead, and on the top center of the head.

2. With an electrode cap (shown in the picture on the left); think of this like a swim cap covered in buttons that the electrodes snap into. With this set-up, electrodes are also placed behind each ear and around the eyes.

Here’s what to expect if you participate in an EEG study:

1. Preparation

You’ll sit in a chair and have the five electrodes or the EEG cap placed on your head. A conductive gel is applied to the electrodes to ensure proper connection between your scalp and the sensors. Headphones with foam earbud tips will be placed in both of your ears.

2. Experiment

You will be comfortably seated in a chair facing a TV screen that will either play a muted movie (with captions) or present a visual task that is associated with the sounds playing through your headphones. You will be instructed to remain relaxed and to move as little as possible while the sounds are playing. The researcher can see and hear you through a video camera to monitor you during testing. The room lights will be turned off and the door will be closed but not locked.

3. After the experiment

The electrodes will be gently removed by the researcher. For EEG experiments using the cap, you will have a significant amount of remaining gel throughout your hair once the cap is removed. We encourage our participants to plan in advance for this, such as bringing hair supplies (a brush, hat, head scarf) to manage your hair until you can get home to wash it. We have rinse bottles, hair combs, towels, and a sink/restroom available if you’d like to rinse your hair before your departure.

Pupillometry

Pupillometry is a research method that measures pupil size to study cognitive processes like listening effort, attention, and more. In the SoundBrain Lab, we measure a participant’s pupil size while they perform a listening task, such as categorizing different speech sounds or listening to sentences mixed with background noise.

Here’s what to expect if you participate in a pupillometry study:

1. Preparation

You’ll sit in a chair and rest your chin and forehead on a cushioned platform fixed to the desk in front of you. Headphones will be placed over your ears. We ask our participants to come to their lab visit with no eye makeup on, as it can affect the quality of the pupil measurement. We keep individually-packaged makeup remover wipes on hand in case you forget!

2. Experiment

You will be comfortably seated in a chair facing a computer screen that will show visual stimuli associated with the auditory task you are asked to perform. You will be instructed to remain in a stable position during the task so the eye-tracking equipment can accurately measure your pupil size. The researcher will be able to see and hear you from outside the test room through a video camera to monitor you during testing. The room lights will be turned off and the door will be closed but not locked. Breaks are built into testing to allow you to rest your eyes and stretch.