cryptic 25,511

[twiglet3]

2d- varying tones are to vibraet sympathetically
r?????t?

4d- frigid flighty creature 6,4
a????? t?r? - something tern?

5d- Expose to air for a time in atomic energy research establishment
a????? is this aerate?

17d- in or on charge???? responsible for batting attack

12a- performing well less than one hymn , 2,4
o? s???

[grasscarp]

2 resonate

[twiglet3]

oh is 12a on song?

[grasscarp]

4d arctic tern

[grasscarp]

for 12 a could be

[ladyalex]

4D Arctic tern

5D aerate

17D In charge....don't know of 'on charge' as an expression except to do with mobile phones etc.

12A On song

Didn't know 12d but saw it posted elswhere on this site

[geo0939]

5 and 7 are correct.

[twiglet3]

thankyou very much xxx