Currently, when a voicemail is left, an email containing the transcription and an audio recording of the message is sent to the user. However, when the user reads the email, the voicemail indicator on their office phone changes to reflect the fact that they heard the voicemail. It is possible to modify those settings.
The PSU News article below discusses the voicemail transcription email feature and at the bottom of the link, it contains a link to the PSU KB and on the KB article, there is a request form to change the preferences for the voicemail notifications.
Notification Change Form: