The impact of phrasal prosody on glottalization is documented in many publications ([4], [7]). Besides prosodic boundary and stress, other influencing factors such as the speaking style have been studied in [8]. The work reported here examines the relationship between the objective preference of listeners and the occurrence of speakers' glottalization, speech data employed for this purpose were phonetically balanced sentences in six languages. Additional experiment, concerning the influence of reading style on glottalization, was conducted with American words and phrases read with monotone and isolated Chinese syllables segmented from carrier sentences. Evaluating the statistics from this investigation, we can come to following conclusions: (a) The occurrence and degree of glottalization can be different across speakers. (b) As an prosodic effect, glottalization is not undesired for speakers. (c) A well-defined reading style can increase the occurrence.