d (Pinyin) t (IPA)

Voiceless alveolar stop
The voiceless alveolar stop is a type of consonantal sound used in many spoken languages. The symbol in the International Phonetic Alphabet that represents voiceless dental, alveolar, and postalveolar stops is ⟨t⟩, and the equivalent X-SAMPA symbol is t. The dental stop can be distinguished with the underbridge diacritic, ⟨t̪⟩, the postalveolar with a retraction line, ⟨t̠⟩, and the Extensions to the IPA have a double underline diacritic which can be used to explicitly specify an alveolar pronunciation, ⟨t͇⟩.
The [t] sound is a very common sound cross-linguistically;[1] the most common consonant phonemes of the world's languages are [t], [k] and [p]. Most languages have at least a plain [t], and some distinguish more than one variety. Some languages without a [t] are Hawaiian (except for Ni‘ihau; Hawaiian uses a voiceless velar stop when adopting loanwords with [t]), colloquial Samoan (which also lacks an [n]), and Nǁng of South Africa.

Features

• Its manner of articulation is occlusive, which means it is produced by obstructing airflow in the vocal tract. Since the consonant is also oral, with no nasal outlet, the airflow is blocked entirely, and the consonant is a stop.
• Its place of articulation is alveolar, which means it is articulated with either the tip or the blade of the tongue at the alveolar ridge, termed respectively apical and laminal.
• Its phonation is voiceless, which means it is produced without vibrations of the vocal cords. In some languages the vocal cords are actively separated, so it is always voiceless; in others the cords are lax, so that it may take on the voicing of adjacent sounds.
• It is an oral consonant, which means air is allowed to escape through the mouth only.
• It is a central consonant, which means it is produced by directing the airstream along the center of the tongue, rather than to the sides.
• The airstream mechanism is pulmonic, which means it is articulated by pushing air solely with the lungs and diaphragm, as in most sounds.