All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Bashfulness is one of the characteristics of the Muslim woman. Her voice is not an ‘Awrah in itself, but there are some etiquettes that she should observe when talking, among which is that she should avoid being soft in her speech in the presence of non-Mahram men. She should also neither speak loudly nor laugh loudly in their presence, as this is not appropriate for a Muslim woman and it contradicts the bashfulness of the woman. For more benefit, please refer to Fatwa 84462.
On the other hand, distinguishing between laughing and just talking, and saying that it is forbidden to raise her voice when laughing and it is permissible to raise her voice when talking, is something that we do not know any evidence about.
Allaah Knows best.