The term 'high-pitched bark' refers to the sound made by a dog when it is excited or alarmed. This sound can be expressed in three different ways: YIP (3 letters), YAP (3 letters), and YELP (4 letters). A YIP is a short, sharp bark, while a YAP is a longer, more drawn-out bark. A YELP is a loud, high-pitched bark that is often used to express pain or distress. All three of these sounds are considered to be high-pitched barks.