Speed Pitch & Timing

Separate timing problems from pitch problems

Speed, pitch, delay, drift, and channel timing are related, but they are not the same correction. Changing playback speed may alter duration and sometimes pitch, while a time-stretch operation can change duration while trying to preserve pitch. A fixed delay shifts the whole signal by the same amount; drift is different because the offset grows over time. Knowing which problem you have prevents a simple synchronization issue from turning into unnecessary processing.

For video, multi-microphone recordings, or long interviews, measure the offset at more than one point. If the beginning is aligned but the end is not, a one-time delay will not solve it. Likewise, check both channels before applying a stereo timing correction because the mismatch may exist on only one side. After any speed or timing adjustment, review transient sounds such as claps, consonants, or drum hits; they make alignment errors easier to hear.

Practical tips

• Measure synchronization near the beginning and end of a long file to distinguish fixed offset from drift.
• Use sharp events such as claps or clicks as alignment references when speech is too gradual to judge precisely.
• Keep notes of the original duration and correction amount so the process can be reproduced.
• When changing speed, check whether the tool preserves pitch or intentionally changes it.
• After channel-delay correction, listen in mono as well as stereo to catch phase or comb-filtering problems.