Compare the notes directly
A common sus4 chord replaces the third of a triad with the fourth, while a sus2 chord uses the second instead. Csus4 contains C, F, and G; Csus2 contains C, D, and G. Neither basic shape includes the E or E flat that would establish a conventional major or minor third. Play C major, then each suspended version, and listen to the change. Keep the root and fifth consistent so that the different middle note is the main variable in the comparison.
Hear a release without making it a rule
Move Csus4 to C major and listen to F settling down to E. This is a useful example of tension and release, but suspended chords do not always resolve immediately or in that direction. Some arrangements sustain their open quality for a whole phrase. Practice both versions: a brief suspension leading to a triad and a suspended chord held without resolution. Sing a simple melody over each and notice how its notes affect the perceived stability of the harmony. Context determines the role of the sound.
Three D chords with one moving voice
Use standard-tuning guitar shapes xx0232 for D, xx0230 for Dsus2, and xx0233 for Dsus4. Read from the lowest string to the highest and omit the two x strings. The sounding pitch collections are D–F sharp–A, D–E–A, and D–G–A respectively, with some notes doubled. Pick the highest string after each full chord so F sharp, E, and G become easy to locate. On piano, play those three-note collections in the same register.
Build a two-bar figure: Dsus4 on beats one and two, D on beats three and four, then Dsus2 for the whole second bar. Repeat without adding another chord. The G-to-F-sharp motion creates one kind of release; the held E in the next bar creates an open continuation. Now end the second bar with D minor instead. Its F natural shows why the suspended collection by itself did not establish a major quality. Sing each changing note rather than making the exercise a blur of finger movements.
Check the melody and the chart
When AudioChords suggests a suspended label, compare it with the recording at a stable moment. A melody note may create the suspended color while another instrument still plays a third, producing a more complex combined sound. Try a simple voicing and listen in context before editing the label. On your instrument, choose a shape that lets the changing note remain audible rather than burying it beneath a heavy bass. Suspensions are useful expressive options when their motion or openness serves the phrase; they are not decorative symbols to insert automatically whenever a plain chord feels too familiar.
Sus is not the same as add
Do not confuse a modern sus chord symbol with every detail of a classical suspension. In strict voice-leading, a suspension involves preparation, a held note over a harmonic change, and resolution; a guitarist can play Dsus4 without that entire pattern occurring. Also distinguish Dsus2 from Dadd9: the latter retains the third F sharp while adding E. If a recording contains both E and F sharp, a bare Dsus2 shape may be a simplification, not an exact description. Compare the accompaniment with and without the third, listening under the singer, and keep whichever level of detail serves the intended arrangement.