A phoneme is the smallest unit of sound that can distinguish one word from another in a language. For example, the words "cat" and "cot" are distinguished by the phonemes /k/ and /t/, respectively.

Allophones are different pronunciations of the same phoneme. For example, the phoneme /t/ can be pronounced as a voiceless alveolar stop [t] or a voiced alveolar flap [ɾ], depending on its position in a word.

Distinctive features are binary features that distinguish one phoneme from another. The three main distinctive features are voicing, place of articulation, and manner of articulation.

Articulation is the process of converting phonemes into sounds. It involves the movement of the lips, tongue, and other speech organs to produce sounds.

Phonology is the study of the organization of speech sounds in language. It includes the study of phonemes, allophones, distinctive features, and the processes of articulation and perception.

Reduplication is a morphological process, not a phonological process. Assimilation, dissimilation, and metathesis are all phonological processes that can change the sounds of words.

Assimilation is the process of two sounds becoming more similar to each other. For example, the sounds /t/ and /d/ can assimilate to each other to produce the sound [t̪].

Dissimilation is the process of two sounds becoming less similar to each other. For example, the sounds /t/ and /d/ can dissimilate to produce the sounds [t] and [d].

Metathesis is the process of two sounds switching places. For example, the sounds /r/ and /l/ can metathesize to produce the word "frend" instead of "friend".

Elision is the process of deleting a sound. For example, the sound /h/ can be elided in the word "house" to produce the word "ouse".

Deletion rules are not phonological rules. They are morphological rules that delete morphemes from words.

Speech perception is the study of how humans perceive speech sounds. It includes the study of how we recognize phonemes, how we understand the meaning of words, and how we produce speech.

Reduplication errors are not speech perception errors. They are phonological errors that occur when a sound is repeated unintentionally.

Phoneme identification, phoneme recognition, and phoneme perception are all terms for the process of recognizing phonemes in speech.

Context, speaker variability, and listener variability are all factors that affect speech perception.