other speaker/speakers

[haseli22]

Dear native speakers,

In the following sentence, why has the word "speaker" been used in a singualr form? I have read that after "other" plural noun should be used.

If you are listening to a teacher or other speaker, write down the topic.

Thanks.

[5jj]

If we are speaking of one other person or thing, then we use a singular noun.Where did you read that we have to use a plural noun?