## Syntax
```mermaid
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'themeVariables': {
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flowchart LR
Start((START)) --> SOUNDEX[SOUNDEX]:::quoted
SOUNDEX --> End((END))
```
## Purpose
The `SOUNDEX` SQL functions converts a value to the Soundex code as defined on [Wikipedia](https://en.wikipedia.org/wiki/Soundex).
See also [[METAPHONE]] and [[DMETAPHONE]].
Parameters:
- Input (`varchar2`): Text to retrieve the soundex value from.
Returns: A text started with a number and followed by 3 digits.
## Examples
The following example retrieves the Soundex code of `smith` and `smythe`; despite the different spelling the Soundex codes are identical:
```sql
select soundex('smith') soundex1
, soundex('smythe') soundex2
-------- --------
S530 S530
```
The following example retrieves the Soundex code of `Robert`:
```sql
select soundex('Robert')
-------------------
R163
```