Website: https://www.wowforbusiness.com/docs/wow/product-support/voicemail-instructions.pdf
Optimum is the first landline telephone service provider in the U.S. to launch High Definition calling. HD calling is the next generation of voice technology that gives you less background noise, sharper sound quality and increased clarity in your phone conversations. To experience HD calling, customers and call recipients must subscribe to Optimum Voice and use HD-capable handsets.

After creating, the Voicemail Greeting, you can test it by calling to your number from another phone, and see if it is playing correctly or not. Open the Phone App. On the lower screen, tap on the Voicemail option. Select Custom, with this option, you can record the personal voicemail greeting on the iPhone. Tap Record, to start recording the voicemail greeting message on the iPhone. Greeting samples are given in this article below, Once you are done with recording, tap Play to listen. Lastly, if everything is alright, and custom voicemail recording is perfect, then tap Save.
When clients or customers want to learn more about your business, oftentimes after checking out your website and social media, if they have further questions regarding your products or services, they’ll pick up the phone and call.