The ORCA Nonsense Syllable Test (ORCA-NST)

The advanced features in today’s hearing aids call upon the use of new tests to assess the effectiveness of those features. We developed a computerized nonsense syllable test to focus on high frequency speech sounds identification. 

Hearing aid wearers fit with an open fit instrument, extended bandwidth or a processing algorithm such as frequency transposition may perform adequately on standard speech evaluation using conventional word lists and sentence tests. This poses a challenge to the clinician on how to demonstrate benefit for these types of fittings. 

We propose the use of a nonsense syllable test recorded by a female speaker as an alternative tool. By using nonsense syllables, the various cues of real words and sentences are not available to the listener to aid in guessing the correct response. This new test consists of C-V-C-V-C nonsense syllables which allows a consonant to be presented in initial, medial and final positions. Consonants used in the test are / p, t, k, b, d, g, m, n, ŋ , f, v, θ , ð, s, z, Ʒ , ∫ , ʧ , l, w, wh, ʤ , j, h, ɹ /. There are 5 vowels used / i, ə, æ, ʌ , u/ covering the full range of vowel formant frequencies. This is an open set test where each item is preceded by the phrase “Please say the word…” by the talker. The test is controlled via computer which allows a random presentation each time the test is given. Scoring is also conducted on the computer which permits the results to be seen immediately with analysis by phoneme class. 

Those interested in obtaining a copy of the ORCA-NST for research purposes may request a copy by contacting us.

Screen Shots of the ORCA-NST

Test Screen
The Test screen is what you will see while administering the ORCA NST. The stimulus is seen across the top of the screen in phonetic form. If the subject gets the entire stimulus correct, the clinician simply clicks the “Next” button (Green) to proceed to the next test item.

If the subject gets a phoneme wrong, the clinician clicks on the phoneme repeated by the subject and it will appear as an error (Red Box). If the subject adds phonemes that are not in the test item, the clinician can use the blank drop down menus to add the phoneme said by the subject.
Composite Results
The composite results screen displays the % correct of the test. The results will show % correct for in several categories including “Total Phoneme Score” as well as individual phoneme classes.