CASPER: A Large Scale Spontaneous Speech Dataset

The majority (67.79%) reported speaking US English, reflecting the dataset's primary demographic. However, a significant proportion of non-native and regionally influenced English varieties are also present, including Chinese Mandarin-influenced English (4.81%), UK English (5.29%), and Indian English (2.88%). Additionally, 14.42% of participants did not specify an accent, indicating either an omission or variability in self-identification. The participants' accent and native language are based on their self-identification, for example, the number of speakers with an Arabic accent may differ from the number with Arabic as their native language. Age distribution reveals that younger speakers are over-represented, with 57.21% of participants in the 18-29 age range and 23.56% in the 30-39 range.