his cheerful whistling indicated that he enjoyed his work.
Examples of whistling
whistling
An indie, folk, alt-country sound that will have you whistling all the way home.
From the nznewsuk.co.uk
The whistling, more than anything, has become an essential part of his identity.
From the sacbee.com
Unfortunately, there's not much of an industry or legacy or canon for whistling.
From the sacbee.com
You will next accuse me of whistling past the graveyard, unless I miss my guess.
From the evangelicaloutpost.com
Some 8 feet across, the zinc-colored object made a whistling noise as it landed.
From the foxnews.com
We held hands, whistling, until she grew too tired and it was time for me to go.
From the thisismoney.co.uk
You lean out of the window and feel the cold bright air whistling past your face.
From the telegraph.co.uk
The delegates at Xcel Energy Center greeted him warmly, standing and whistling.
From the washingtonpost.com
Researchers believe she was trying to imitate the sounds of whistling zookeepers.
From the abcnews.go.com
More examples
The sound made by something moving rapidly or by steam coming out of a small aperture
Make whistling sounds; "He lay there, snoring and whistling"
Move with, or as with, a whistling sound; "The bullets whistled past him"
A small wind instrument that produces a whistling sound by blowing into it
Acoustic device that forces air or steam against an edge or into a cavity and so produces a loud shrill sound
Move, send, or bring as if by whistling; "Her optimism whistled away these worries"
A whistle or call is a simple aerophone, an instrument which produces sound from a stream of forced air. It may be mouth-operated, or powered by air pressure, steam, or other means. Whistles vary in size from a small slide whistle or nose flute type to a large multi-piped church organ.
Whistle was a 1980s hip hop and R&B group consisting of Jazzy Jazz, Kool Doobie, and DJ Silver Spinner. They later brought in Kraze and then Terk after Kool Doobie left the group to go solo. Their biggest hit was "(Nothing Serious) Just Buggin" in 1986. ...
Whistle is the registered trade name of a chemical mixture used in the demilitarization of chemical warfare agents. It is a liquid which can be used to replace sodium hypochlorite or sodium hydroxide in some applications.