Simultaneous Interpreting

There are 2 main types of interpreting: consecutive and simultaneous interpreting.
As a Japanese interpreter I am able to do both.

Consecutive Interpreting
During consecutive interpreting the speaker will speak for a minute or 2 as the interpreter takes notes.
Then the interpreter will repeat back what the speaker said following the notes. This pattern continues until the speaker has completed there speech.
This method is also common in group meetings or 1 on 1 meetings. Conceptually the speaker fills a bucket and then the interpreter pours the bucket out when it's full. This method requires a lot of concentration and good note taking skills.

Wireless Transmitter / Receiver

Conference Simultaneous Interpreting

Simultaneous Interpreting
With simultaneous interpreting the interpreter will speak at the same speed as the speaker. The interpreter is speaking into a wireless transmitter mic and the audience listens on wireless receivers with earpieces.
The speaking of both the interpreter and speaker is real time with no lag. No notes are required to be taken by the interpreter. In a standard configuration there are 2 interpreters that partner up during the interpreting.
Every 15-20 minutes the interpreters will switch off. This allows for a much higher level of accuracy. Without a partner the level of accuracy will drop due to mental fatigue.

With simultaneous interpreting it's recommended that the interpreters utilize a table top booth in order to isolate their voices from the audience members that don't require an interpreter. Depending on the venue the interpreters will also require a headset that allows them to clearly hear the speaker's words. Without this the level of accuracy will be diminished.

Contrary to popular belief simultaneous interpreting tends to be easier to do than consecutive interpreting because the interpreter only needs to concentrate on the sentence being spoken at the moment it is spoken and isn't required to assemble long sequences on the fly.