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    /p/ vs /b/: pack vs back

    The voiceless /p/ and voiced /b/ separate a huge number of words: pear/bear, pig/big, cap/cab. English relies on the puff of air (aspiration) at the start of /p/ to keep them apart.

    • High impact
    • 7 pairs
    • Three voices

    1 / 10

    Which word do you hear?

    See the difference

    Hold a tissue in front of your lips: it should jump on 'pack' and stay still on 'back'. At word ends, keep /b/ gently voiced; 'cab' must not become 'cap'.

    p

    as in pack

    Lips
    Pressed together
    Tongue
    Resting; the lips do the work
    Voice
    Off: only air
    Air
    Stopped, then released in a small burst
    Learn p

    b

    as in back

    Lips
    Pressed together
    Tongue
    Resting; the lips do the work
    Voice
    On: feel your throat buzz
    Air
    Stopped, then released in a small burst
    Learn b

    All 7 pairs

    In a sentence

    Hardest for speakers of

    Questions

    What is the difference between pack and back?
    pack /pæk/ uses the /p/ sound while back /bæk/ uses /b/. Hold a tissue in front of your lips: it should jump on 'pack' and stay still on 'back'. At word ends, keep /b/ gently voiced; 'cab' must not become 'cap'.
    Which learners find the /p/ vs /b/ contrast hardest?
    It is most challenging for Arabic, Korean, Indonesian, Farsi speakers, whose first languages don't separate these two sounds.