The Effect of Speech Variability on Tonal Language Speakers' Second Language Lexical Tone Learning

Area of Science:

• Linguistics
• Second Language Acquisition
• Phonetics

Background:

• Speech variability aids non-tonal language speakers in learning lexical tones.
• The benefit of speech variability for tonal language speakers learning second language (L2) lexical tones is unknown.
• Previous research suggests speech variability's effectiveness is limited to new items.

Purpose of the Study:

• To investigate if speech variability benefits tonal language speakers learning L2 lexical tones.
• To test the hypothesis that speech variability primarily aids acquisition of L2 tones dissimilar to the first language (L1) tones.

Main Methods:

• Native Mandarin speakers (tonal L1) were trained to learn Cantonese tones.
• Training involved either high variability (HV) or low variability (LV) speech materials.
• Learning performance was compared between HV and LV groups.

Main Results:

• Speech variability partially supported the hypothesis, benefiting production of Cantonese low and mid-level tones.
• Mandarin speakers likely used L1 representations for similar Cantonese tones, limiting variability's impact.
• A perception-production discrepancy was observed, where perceptual gains did not guarantee production improvements.

Conclusions:

• Speech variability's benefit in L2 lexical tone learning for tonal speakers is limited, especially for tones with L1 counterparts.
• L1 interference and reliance on existing mental representations can mitigate the effects of speech variability.
• Improved L2 tone perception does not automatically translate to improved production.