How to Send a Voice SMS
- 1). Find out if your network service provider supports voice SMS. If available, ask the provider how to subscribe to the service. You can also find this information on the network provider's website, along with the cost per voice SMS.
- 2). Dial "*" or "**" followed by the recipient's phone number, for instance **555-555-5555.
- 3). Press the "Call" button on your phone.
- 4). Follow the voice prompts and record your SMS (mostly up to 30 seconds).
- 5). Hang up after completing the recording.
Source...