Auditory Processing (CAP) Evaluation

There are several areas of auditory processing that are evaluated, including binaural separation and integration (the ability to separate or integrate what is heard in each ear), auditory closure (the ability to use redundancies inherent in speech to fill in missing portions of speech), and temporal ordering (the ability to perceive the order of sounds). Several tests can be performed, including:

• Willeford Competing Sentences Test
• Dichotic Digits Test
• Filtered Speech Test
• Time-Compressed Speech Test
• Frequency Patterns Test
• Duration Patterns Test
• QuickSIN Speech in Noise Test

The results of these tests allow us to diagnose auditory processing dysfunction and determine the area of auditory processing that requires remediation.  An auditory processing deficiency can encompass more than one area of auditory processing function and usually specific patterns of weakness are evident for different auditory processing dysfunctions

Willeford Competing Sentences Test presents one sentence to the designated ear at a quieter volume and another sentence to the other ear at a louder volume, simultaneously.  The patient is instructed to repeat the sentence heard in the designated ear.  Ten sentences are presented with the right ear designated and ten are presented with the left ear designated.  This is a dichotic speech test designed to assess binaural separation.

Dichotic Digits Test presents a pair of numbers to each ear simultaneously.  The patient is instructed to repeat the numbers heard in both ears (4 numbers) following their presentation.  This is a dichotic speech test designed to assess binaural integration.  This test does not rely as heavily on language as the competing sentences test.  It can also be performed with a single number presented to each ear if the test is too difficult.

Filtered Speech Test presents words to one ear that have been passed through a low-pass filter of 1000 Hz, eliminating the higher frequency speech sounds.  The patient is instructed to repeat each word following its presentation.  The test is repeated with a different word list to the other ear.  This is a monaural low-redundancy speech test designed to assess auditory closure.

Time-Compressed Speech Test presents words to one ear that have been time compressed by 45% with a .3-second reverberation introduced.  The patient is instructed to repeat each word following its presentation.  The test is repeated with a different word list to the other ear.  This is another monaural low-redundancy speech test designed to assess auditory closure.

Frequency Patterns Test presents sets of three tones that vary in pitch to both ears.  The patient is instructed to state the pitch of each tone in the correct sequence (for example, “high, high, low”) following the presentation of each set.  This is a temporal processing test that assesses temporal ordering.  This test can also be administered without using words, removing the language component of the test response.  The patient is instructed to hum, as opposed to label, the pitch of each tone following the presentation of each set. 

Duration Patterns Test presents sets of three tones that vary in duration to both ears.  The patient is instructed to state the length of each tone in the correct sequence (for example, “long, long, short”) following the presentation of each set.   This is another temporal processing test that assesses temporal ordering.  This test can also be administered without using words, removing the language component of the test response.  The patient is instructed to hum, as opposed to label, the length of each tone following the presentation of each set.

QuickSIN Speech in Noise Test presents sentences and background noise at varying signal to noise ratios (SNRs) to both ears.  The SNRs increase in 5 dB steps from a +25 dB SNR (very easy) to a +0 dB SNR (very difficult).  Two sets of these 6-sentence groups are presented to both ears together, and the scores are averaged to determine a SNR loss.  The higher the SNR loss, the greater the impact background noise will have on speech understanding.