RAW DATA form - Speech Auditory Brainstem Responses: Effects of Background, Stimulus Duration, Consonant-Vowel, and Number of Epochs

Speech Auditory Brainstem Responses: Effects of Background, Stimulus Duration, Consonant-Vowel, and Number of Epochs

Ghada BinKhamis, Agnès Léger, Steven L. Bell, Garreth Prendergast, Martin O’Driscoll, and Karolina Kluk

doi: 10.1097/AUD.0000000000000648

(Please site above article)

Description of raw EEG (speech-ABR) data main folder, subfolders, and raw EEG files

Folder Information

Main folder:

• Contains 144 subfolders with raw data from 12 participants

Subfolder names:

• Each subfolder starts with the participant code
  • S01, S02, S03, S04, S05, S06, S07, S08, S09, S10, S11, S12

• Next is the stimulus duration:
  • 40ms, 50ms, 170ms
• Next is the CV used to evoke speech-ABRs
  • ba, da, ga
• And finally the background condition 
  • quiet, noise

Example subfolder names:

• S01 40ms da noise:Participant number 1, speech-ABRs in response to the 40ms [da] in background noise
• S07 170ms ga quiet:Participant number 7, speech-ABRs in response to the 170ms [ga] in quiet

Each participant has 12 subfolders:

1. S__ 40ms da quiet 
2. S__ 40ms da noise
3. S__ 50ms da quiet
4. S__ 50ms da noise
5. S__ 50ms ba quiet
6. S__ 50ms ba noise
7. S__ 50ms ga quiet
8. S__ 50ms ga noise
9. S__ 170ms da quiet
10. S__ 170ms da noise
11. S__ 170ms ba quiet
12. S__ 170ms ga quiet

Each participant subfolder contains four ‘.mat’ files, ‘.mat’ file names:

• Each ‘.mat’ file starts with the participant code
  • S01, S02, S03, S04, S05, S06, S07, S08, S09, S10, S11, S12 
• Next is the stimulus duration:
  • 40ms, 50ms, 170ms
• Next is the CV used to evoke speech-ABRs
  • ba, da, ga
• Next is ‘noise’ if background condition was noise
• Next is the stimulus polarity
  • Pos for positive/standard
  • Neg for negative (reversed polarity stimulus)
• And finally is the recording number for that polarity
  • R1 is the first recording
  • R2 is the second recording

Example ‘.mat’ file name:

• S04 50 ba Neg R1:Participant number 4, speech-ABR in response to the 50ms [ba] in quiet, reversed polarity stimulus, recording number one 
• S02 40 da noise Pos R2:Participant number 2, speech-ABR in response to the 40ms [da] in background noise, standard/positive stimulus, recording number two

File Information:

Description of ‘.mat’ files that can be accessed and processed using MATLAB (MathWorks):

Each ‘.mat’ file is a structure that contains the following fields:

• The first nine fields are informational, for example:
  • xunits: ‘s’ indicates that the recording time window is in seconds, conversion to milliseconds would be required to plot the data in milliseconds
  • start: ‘0’ indicates that both stimulus and recording start at 0 seconds
  • points: 1800is the number of sample points for speech-ABRs to the 40ms da, this number will be 2200for the speech-ABRs to the 50ms stimuli (ba, da, ga), and 4600for the speech-ABRs to the 170ms stimuli (ba, da, ga)
  • chans: 2 is the number of channels (channel 2 is the ipsilateral channel)
  • frames: 3000 is the number of epochs
• The last filed ‘values’is what contains the raw EEG data (1800x2x3000)
  • 1800 is the number of samples
  • 2 is the number of channels (channel one is recorded from the left ear lobe (A1) and channel two is from the right ear lobe (A2))
  • 3000 is the number of epochs
  • The field ‘values’ for speech-ABRs to the 50ms stimuli is 2200x2x3000 and for speech-ABRs to the 170ms stimuli is 4600x2x3000.
• Stimulus starts at 0 seconds per epoch, pre-stimulus baseline may be extracted from the end of each epoch (i.e. before the next stimulus).

Data is recorded in Volts and will need to be converted to Micro Volts

Date of data collection: May to November 2016