BKB-SIN Methodology

The BKB-SIN contains 18 List Pairs that are equated for difficulty. Each List Pair has two lists; both lists of the pair must be administered, and the scores averaged, for valid scoring. Each List Pair takes approximately three minutes to administer and score. Results are compared to normative data to obtain the SNR Loss.

  • List Pairs 1-8 have ten sentences in each list, with one sentence at each SNR of: +21, +18, +15, +12, +9, +6, +3, 0, -3 and -6 dB. These List Pairs can be used with all listeners.
  • List Pairs 9-18 have eight sentences in each list, with one sentence at each SNR of: +21, +18, +15, +12, +9, +6, +3 and 0 dB. These provide ten additional equivalent List Pairs that can be used for cochlear implant patients and those with significant SNR loss. These lists are not recommended for normal-hearing listeners, since a test floor effect will occur.


A verbal "ready" cue precedes each sentence. The first sentence in each list has four key words, and the remaining sentences each have three. Key words are underlined on the score sheets.

  • Give one point for each key word repeated correctly. Put the total correct for each sentence on the line provided.
  • Subtract the total correct for each list from 23.5 to obtain the SNR-50 (signal-to- noise ratio for 50% correct).
  • Average the SNR-50 scores for both lists of the List Pair. When administering more than one List Pair, average the List Pair scores.
  • Compare the List Pair score to the age-related norms to determine SNR Loss.

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