Phonemic symbols are visual representations of the speech sounds (phonemes) that we produce as we speak. Although there are multiple alphabets of phonemic symbols, the International Phonetic Alphabet (IPA) is the most widely used in the fields of linguistics and speech-language pathology. Below is a chart of consonant phonemic symbols from the IPA.
(From https://www.internationalphoneticassociation.org/content/full-ipa-chart)
The Americanist Phonetic Notation, also known as the North American Phonetic Alphabet (NAPA) or American Phonetic Alphabet (APA) is a system of notation occasionally used by linguists in North America and others who are studying certain Slavic or Native American languages. The consonant symbols of the APA can be found in the charts below.
(From: http://www.ello.uos.de/uploads/PhoneticsandPhonology/APASymbols.pdf)
(From: http://www.ello.uos.de/uploads/PhoneticsandPhonology/APASymbols.pdf)
These charts provide a one-to-one correspondence between a sound and a visual representation.
Advice for Identifying and Memorizing Symbols (Using Standard American English)
One of the more difficult tasks in learning how to transcribe speech sounds is to understand the difference between a ‘symbol’ and ‘orthography’ (or spelling). Since phonemic symbols are visual representations of the sounds we make when we speak, one of the best methods of practice for studying these symbols is to pair visual and auditory information. Start with the symbols that have the most apparent correspondence to common sounds in Standard American English (e.g., /p/, /b/, /g/, etc.). Try using flashcards or practicing with the IPA chart. Saying symbols out loud or practicing aloud with friends and classmates can help make connections between the symbols and the sounds they represent. For the more complex sounds or sounds with multiple orthographic representations in written English (e.g., /f/ → phone, laugh, feel), try practicing by pairing the phonemic symbol with those different orthographic representations in isolation (e.g., /ʧ/ → ch).