Vocal Loading in Speaking a Foreign Language.

AIMS

This study investigated whether speaking a foreign language affects the subjective notions of vocal fatigue, and whether acoustic measurements reveal a higher vocal loading.

METHODS

The speech samples of 20 native Finnish-speaking and 23 native English-speaking subjects were recorded in Finnish and in English. From the speech samples, fundamental frequency, equivalent sound level, total duration of voiced speech, speech rate, alpha ratio and L1-L0 level difference were analyzed. Vocal doses were calculated.

RESULTS

According to subjective notions, the voice gets tired more quickly when speaking a foreign language. The mean fundamental frequency increased but the speech rate and total duration of voiced speech decreased significantly when speaking a foreign language. Thus, the vocal doses decreased.

CONCLUSIONS

The subjective sensations of increased vocal fatigue may be due to increased mental stress rather than to higher vocal loading. However, a trend that speaking a foreign language may involve more loading was found in L1-L0 level difference and in the doses normalized to time dose. Longer speech samples should be studied. Voice quality-based indicators of vocal loading are worth testing in addition to the measures based on the amount of voicing in speech.