Neither. You can hear them if you listen carefully, just the recording tech plus lack of amplification makes it harder than modern music.[1] Source: have degre

Neither. You can hear them if you listen carefully, just the recording tech plus lack of amplification makes it harder than modern music.[1] Source: have degree and postgrad in jazz and used to be a bass player. Have made transcriptions of early bass players from original recordings. (by ear without any kind of fancy tech) [1] and the playing technique for various reasons.