Masking Release for Igbo and English

In this research, we explored the effect of noise interruption rate on speech intelligibility. Specifically, we used the Hearing In Noise Test (HINT) procedure with the original HINT stimuli (English) and Igbo stimuli to assess speech reception ability in interrupted noise. For a given noise level, the HINT test provides an estimate of the signal-to-noise ratio (SNR) required for 50%-correct speech intelligibility. The SNR for 50%-correct intelligibility changes depending upon the interruption rate of the noise. This phenomenon (called Masking Release) has been studied extensively in English but not for Igbo – which is an African tonal language spoken predominantly in South Eastern Nigeria. This experiment explored and compared the phenomenon of Masking Release for (i) native English speakers listening to English, (ii) native Igbo speakers listening to English, and (iii) native Igbo speakers listening to Igbo. Since Igbo is a tonal language and English is a non-tonal language, this allowed us to compare Masking Release patterns on native speakers of tonal and non-tonal languages. Our results for native English speakers listening to English HINT show that the SNR and the masking release are orderly and consistent with other English HINT data for English speakers. Our result for Igbo speakers listening to English HINT sentences show that there is greater variability in results across the different Igbo listeners than across the English listeners. This result likely reflects different levels of ability in the English language across the Igbo listeners. The masking release values in dB are less than for English listeners. Our results for Igbo speakers listening to Igbo show that in general, the SNRs for Igb