Matthew H. Davis and Ingrid S. Johnsrude (2003)

Hierarchical Processing in Spoken Language Comprehension

The Journal of Neuroscience, 23(8), p.3423-3431

Stimuli:

Three forms of distorted, yet intelligible speech were used in the study. The three forms of distortion (and normal speech) are shown in the spectrograms below.

Click on the spectrogram to hear an example sentence in each form of distortion (and as normal speech):

The distorted example sentences above are all of medium intelligibility. For each form of distortion, three levels of intelligibility were constructed: low intelligibility (~20% words reported correctly from each sentence), medium intelligibility (~65% words reported correctly), high intelligibility (~90% words reported correctly). The intelligibility of each form of distortion was assessed from a pilot behaviuoral study in which participants had to either type the words heard in each sentence or give a 9 point rating of intelligibility. In both the pilot study and the fMRI study, report scores and subjective ratings were closely correlated.

In the graph below, you can click on a data point to play an example speech sound with that type and level of distortion.

Or click the speaker in the table below:

	Segmented Speech	Vocoded Speech	Speech in Noise		Normal Speech
High Intelligibility
Medium Intelligibility
Low Intelligibility
Signal Correlated Noise

All the speech distortions were created using Praat software with assistance from Paul Boersma and Chris Darwin. If you would like to find out more about any of the three forms of distortion please contact matt.davis@mrc-cbu.cam.ac.uk.

You can read the abstract of the paper, or request a pdf by emailing: matt.davis@mrc-cbu.cam.ac.uk

This page was created on 21st March 2003. Comments and suggestions to matt.davis@mrc-cbu.cam.ac.uk.