Faltering of the voice resulting from wonder was exhibited by Brahmā. It is said in Śrīmad-Bhāgavatam, Tenth Canto, 13th Chapter, 59th verse that, after bowing down before Lord Kṛṣṇa, when Brahmā began to rise he prayed to the Lord in a faltering voice.
In the Tenth Canto, 29th Chapter, 27th verse, another example of faltering of the voice was exhibited by the gopīs when they came to Kṛṣṇa, desiring to dance with Him. Kṛṣṇa asked them to go back to their husbands and homes. The gopīs apparently became very angry and began to talk to Kṛṣṇa with faltering voices.
In the Tenth Canto, 39th Chapter, 48th verse, of Śrīmad-Bhāgavatam a faltering voice due to jubilation was exhibited by Akrūra when he was shown all of the Vaikuṇṭha planets resting within the River Yamunā. When Akrūra understood that Kṛṣṇa was the Supreme Personality of Godhead, he bowed his head to Kṛṣṇa's lotus feet and with folded hands began to pray in a faltering voice. There are also examples of faltering of the voice caused by fearfulness.
One of Kṛṣṇa's friends praised Him thusly: "My dear friend, Your flute was given to Your servant, Patrī, and when I asked him to return it he began speaking in a faltering voice, and his complexion became yellow."
Trembling
When Kṛṣṇa was trying to capture the demon Śaṅkha, Rādhārāṇī began trembling out of fearfulness. Similar trembling of the body was exhibited in Sahadeva, the younger brother of Nakula. When Śiśupāla was vehemently blaspheming the Lord, Sahadeva began to tremble out of anger.
Trembling of the body was also exhibited by Rādhārāṇī out of tribulation. Rādhārāṇī trembled as She told one of the gopīs: "Don't joke with this disappointing boy! Please ask Him not to approach Me, because He is always the cause of all grief for us."